Reuben's Home Inspection Blog

Floor Drain Basics

July 28th, 2009 | 264 comments

One of the most common defects that I find in old Minneapolis and Saint Paul houses is a missing cleanout plug in the floor drain – especially during Truth In Sale of Housing Evaluations.  A missing cleanout plug can allow hazardous sewer gas in to the home, and often indicates a clogged floor drain.   To learn why and how, read on.

Trap Diagram 1616 Every plumbing fixture has a trap. The purpose of a trap is to prevent foul-smelling sewer gas from coming back in to the house.  The diagram at right shows a P-trap, which can be found at sinks, showers, and bath tubs.   The left side of the trap connects to the plumbing fixture, and the right side connects to the sewer.  The ‘sewer’ side will have sewer gases present, but the water sitting in the bottom of the trap prevents the sewer gases from entering in to the house.

Floor Drain with water

Floor Drain

Floor drains are no exception. The photo at right shows a floor drain, as viewed from the side.  The shaded portion shows the trap where water will always sit, which prevents sewer gas from coming in.  When you look at an installed floor drain, all that you typically see is the grill on top; the rest of the drain is always buried in the basement floor.

When the drain line gets clogged If the drain line for the floor drain gets clogged, it needs to be cleaned out with a drain cleaning tool. The floor drain has an area which bypasses the trap, which will allow a tool to be inserted in to the drain.  I’ve highlighted this bypass in the photo below, left.   Normally a plug is installed here, because this is an area where sewer gases dwell.  When the plug is removed, sewer gases come in to the house.  After the drain gets cleaned out, the cleanout plug needs to be replaced.   The plug is circled in blue in the photo below, right.

Floor Drain bypass Floor Drain showing cleanout plug

Bad Threads on cleanout hole What if the threads are destroyed? On some older floor drains, the threads that used to accept the cleanout plug are damaged or badly rusted, to the point that it’s impossible to screw in the cleanout plug.  The only acceptable repair for this situation is to install a rubber plug.  One type of plug is a piece of rubber that is sandwiched between two pieces of metal that expand the rubber when tightened together.  The two photos below show a rubber plug before it’s tightened and after it’s tightened.  Another type of rubber plug can be found at Real-Tite Plugs – a company located in Golden Valley.

Loose Cleanout Plug Tight Cleanout Plug

A missing cleanout plug usually means one of two things:

  1. The drain was clogged, someone removed the cleanout plug to clean the drain, and they forgot to put the plug back in.
  2. The bottom of the trap is clogged, and someone removed the cleanout plug to allow water to drain directly in to the sewer, instead of going through the trap.

When the cleanout plug is missing it needs to be replaced, and the floor drain may need to be cleaned out or replaced.  If the drain cannot be cleaned, the entire floor drain needs to be replaced.  When I perform re-inspections on homes in Minneapolis that have had missing cleanout plugs, about one in five floor drains need to be replaced because the drain couldn’t be cleaned out.  This is an expensive repair, as it involves breaking up the concrete in the basement floor, replacing the drain, then pouring new concrete.

Just for fun, here are a few photos of missing cleanout plugs that I’ve taken within the past couple months.

Missing Cleanout Plugs

For more information on common Truth In Sale of Housing defects, click on any of the links below.


Reuben Saltzman, Structure Tech Home Inspections – Email – Minneapolis Home Inspector



264 responses to “Floor Drain Basics”

  1. home inspection sussex county
    July 31, 2009, 11:12 am

    very informational!

  2. Rick Absi
    August 17, 2009, 6:46 am

    Great article. I’ve been struggling with a sewer odor in our house for a long time, and I think I’ve identified the floor drain as the source. The floor drain is used for condensate from the evaporator coil on the air conditioner. It’s located in the garage. The house is 11 years old, built slab-on-grade. We’re connected to city water/sewer.

    I’ve tried to look for the cleanout plug in the drain, but I can’t find it. Is it possible that I have a floor drain without a cleanout? Or am I just missing something? I greatly appreciate your input. The smell is really bad and very annoying! Thank you.

  3. Reuben Saltzman
    August 17, 2009, 5:03 pm

    Rick – some floor drains don’t have cleanout plugs. Maybe the trap has dried out? If the water dries out, you’ll get sewer gas. Send me a photo or two, and I’ll give you an opinion and post the photos.

  4. Chris Anstey
    January 4, 2010, 10:17 pm

    I have just recently removed the drain cover from the floor drain in the basement, the drain is blocked but water does seap out very slowly . I noticed this plug on the side of the drain and now understand what it is for . is there any special technique for removing the plug from the drain wall. Drain is cast approximately 60 years of age . Would draino in hoy water help with clearing the floor drain. Any assistace would be appreciated.

  5. Reuben Saltzman
    January 5, 2010, 6:25 am

    Most old plugs are threaded in place, and can be removed with a pipe wrench. I don’t think any type of liquid drain cleaner would help – I’ve never had any luck with liquid drain cleaners. They’re supposed to work on hair, and I’ve found them to do a marginal job of that. I’d use a ‘snake’, which is slang term for a mechanical drain cleaning tool.

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  7. Mark Schreiber
    March 4, 2010, 2:17 pm

    As a response to Rick’s problem and anyone else that is experiencing sewer gases and odors from their floor drains; this is generally because the water traps in the pipes have dried out. This allows the gases to enter into your home or even into your place of work. Over time, the water trap will evaporate if not regularly used or flushed. I have found and researched into a product called TheSureSeal which you can easily place within your floor drain, whether in your bathroom, shower, or even in the water heater drain. TheSureSeal is a device that you can place in your drain in just a matter of minutes. It is very effective and easy to use.

  8. Reuben Saltzman
    March 4, 2010, 5:55 pm

    Mark – I debated posting your comment because it sounds like you’re trying to sell your goods on my blog. Come now, you didn’t really find and research this product; you’re selling it, right?

    I posted your comment anyways because I’ve never seen this product before. What advantages would this product have over pouring some anti-freeze in to the drain, probably at a fraction of the cost?

  9. Mark Schreiber
    March 11, 2010, 3:25 pm

    Okay well first of all “research the product”. It’s something everyone does. If you go into something blind and don’t research it then you’re sometimes in for a rude awakening.
    And to answer your question, it’s not that it kills bacteria which is I suppose what anti-freeze would do, but anti-freeze doesn’t solve the problem of failed water traps. This device prevents the odors that the sewer would otherwise bring up with a failed trap scenario.
    Secondly, putting solutions into your pipes can only be worse for the environment. This is chemical free.

  10. Reuben Saltzman
    March 11, 2010, 4:05 pm

    Very good, thanks.

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  12. David
    April 18, 2010, 5:35 am

    I wonder if you can tell me how would I know for sure that a drain in my basement goes to the sewer or if it just goes to a dry bed? I started making a shower around it and had to stop until I figure that one out. I opened the drain cover and there was a 4 inch tube that looked like a pencil that was coming out of the side that felt like it was soft copper as I could bend it. The house is 30 years old in Canada the drain goes down about a foot and turns. There was also a rough in for a toilet and sinc….any help would be appreciated as this project has been on stall for the past year now.

  13. Reuben Saltzman
    April 21, 2010, 5:09 am

    Hi David,

    If you have a main sewer cleanout hole right before your main drain leaves the house, try removing the cover, then pour a bunch of water down the floor drain. If it goes out to the sewer, you’ll be able to see the water from the cleanout hole.

    The soft copper tube that you’re referring to is probably a trap primer – it’s a device that will periodically dump a little bit of water in to the floor drain to prevent it from drying out.

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  15. David
    August 25, 2010, 6:31 am

    You are a brilliant man as I have been trying to figure this out for a couple of years and nobody had a clue how to figure out my problem but you did…..THANK YOU….MY DRAIN GOES TO THE SEWER.!!!!

  16. Jeff
    October 1, 2010, 11:14 am

    My basement floor drain (which has a cleanout) needs water poured in it every other day when the heater or a/c isn’t running to stop sewer gases. My house was built in 1961. Do these traps ever need replacing because of rusting through or cracking? If so, how big of a job is it? The drain is in a concrete floor.

  17. Reuben Saltzman
    October 1, 2010, 2:08 pm

    Hi Jeff,

    Yes, cracks can certainly develop. It sounds like that’s what happened to you. It’s not a quick and easy project to replace the floor drain – you’ll need to break up the concrete in the floor and dig out the dirt under and around the floor drain in order to get it out. After you replace it, you’ll need to pour new concrete.

  18. Jeff
    October 1, 2010, 2:16 pm

    Thanks Reuben

  19. Deanna Synowiec
    October 15, 2010, 7:10 pm

    Sounds like you may be just the person to help me. We have lived in our home for 14 years. We have trees in our area and have had to regularly snake our drains. It works until the next big growing season. So, this, we are accustomed to. Three weeks ago we had a bad sewage back up in the basement and figured, time to snake again. The plumber came out, snaked as usual finding the usual root balls etc, we ran tons of water in the house, flushed toilets repeatedly, spun water out of the washer and poured water down the drain all at the same time to make sure it was all clear. We have had no back ups since, and the surrounding area has been thoroughly cleaned, but we do have an awful sewage smell remaining. This smell can permeate the whole house and in order to keep it at bay we have to close the basement door. Knowing that the trap can go dry, we have repeatedly poured buckets of water down the the drain (it’s the one by the furnace that leads out to the main) We have even used a bleach and water solution in the drain. All of this only works for about 24-48 hours. We are at a loss as we have not had this problem post snaking in the last 14 years (and we have done plenty of snaking-sometimes twice per year). What advice do you have for this? I pray it isn’t the dreaded break up the basement floor and spend your life savings situation. Thank you for your reply in advance-now, be my hero!

  20. Reuben Saltzman
    October 16, 2010, 5:14 am

    Hi Donna,

    When your plumber snakes out your main drain line, I’m sure he or she is removing the cleanout plug from the main waste line, which is probably a three or four inch plug.

    I don’t think your issue is a dry trap – if you look in your floor drain and you can see water, you don’t have a dry trap. Your issue is probably a missing cleanout plug in the main building drain. I don’t know where you’re writing from, but on most older homes here in Minneapolis and Saint Paul, the main cleanout plug is typically located in the floor very close to the water meter.

    Find your main cleanout and make sure the plug is in place. Good luck.

  21. Deanna Synowiec
    October 16, 2010, 3:03 pm

    The plug is in place and nicely fitted. Any other ideas.

  22. Deanna Synowiec
    October 16, 2010, 3:04 pm

    Oops! Forgot to include that we are in Michigan just outside of Detroit. A Cape Sod style bungalow that was built in the 20’s or 30’s.

  23. Reuben Saltzman
    October 17, 2010, 1:14 pm

    So you have a cleanout plug in the main building drain, a cleanout plug in the floor drain, water in the trap of the floor drain… yet you’re still getting sewer gases in the basement.

    I’m out of ideas. I’d say it’s time to call a plumber. Let me know what you find out.

  24. Andy
    November 13, 2010, 7:50 pm

    Thank you, very helpful! Needed to see a diagram of a floor drain, our drain is clogged but I could remove the clean out plug (which I did, and put back) if the floor flooded. The question is do I attempt to clean out the drain knowing this could result in an expensive replacement or just call it quits for now?

    Again, thank you.

  25. Reuben Saltzman
    November 13, 2010, 9:03 pm

    Andy – go ahead and try to clean the drain out. You probably won’t make things any worse.

  26. Heating Service
    December 8, 2010, 8:48 am

    Thank you for this well written advice, very helpful.

  27. roseville pipe clean out
    March 15, 2011, 7:10 am

    A very informative piece.
    I think our drains look better than the ones in the picture.
    Any problem we encounter, if my husband cannot fix it, time to call in reinforcements, a plumber.

  28. george.elaine12 @ floor drains
    July 7, 2011, 6:31 am

    This is a great and informative article. Quite helpful for anyone who is new to fixing floor drains, etc.

  29. Larry Czarnecki
    July 11, 2011, 8:40 pm

    Reuben need your advise please. Can the basement floor drain be snaked? My house is 40 yrs. old. I’ve snaked the clean-out on the side. The drain has water in it but drains VERY SLOW. I live in Apple Valley MN. Am I dealing with a P-trap? What’s you take on this?

  30. Reuben Saltzman
    July 12, 2011, 3:54 am

    Hi Larry,

    Yes, it sounds like you’re dealing with a clogged P-trap. You can certainly shove something in the trap to try cleaning it out, but there is no guarantee that it will work. I personally had to replace a floor drain at my sister’s house because the P-trap was filled with concrete.

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  32. Lynn Syverson
    July 31, 2011, 1:16 am


    I’m hoping you can help me. This evening I ran a load of laundry in my basement washer which drains into the laundry tub only to come down to transfer to the dryer instead finding clean water covering the basement. Took me a while to figure it out as the only place there wasn’t water was by the laundry tub and washer/dryer! I believe it is the floor drain (glad it was clean water) and think it may be because hubby decided to give the laundry tub and it’s drain a thorough cleaning. Must have pushed enough grunge through to create a blockage. Knowing all this, do I follow your snaking method above? This will be my first time so your guidance is much appreciated. I’m a fixer, he’s a “call a repairman.”

  33. Lynn Syverson
    July 31, 2011, 1:40 am

    Just looked in the drain and it’s very deep with no visible clean out plug?

  34. Reuben Saltzman
    August 1, 2011, 3:18 pm

    Hi Lynn,

    Yes, I think that snaking out the drain would be worthwhile; just make sure you have a long enough snake. As for the deep drain with no cleanout plug – some older floor drains just don’t have cleanouts. The drain at your laundry sink should have a cleanout hole, and that pipe probably connects to the same line at the floor drain.

  35. Sinks
    August 11, 2011, 5:39 am

    This is really quite a nice article with regards to the drains, I do appreciate the author for providing such a wonderful piece of information…

  36. Pat
    September 27, 2011, 9:21 am

    Something somewhat related, if the trap dries out and you have a whole house fan running and forget to open the windows, you will pull gasses out of the drain …. stunk the entire house up before I figured out what happened.

  37. Clint Kingsbury
    November 2, 2011, 12:38 pm

    hello, i have a very old house and there seems to be many strange drains in my basement. one has a wingnut type rubber seal, the other side of the basement has a removable over like a lid. these seem not to be the issues…
    the issue i have is in one of my separate rooms in the basement there is a 1ft x1.5ft resovoir that has a removable metal lid on it. just in front of it looks like a drain clean out (not sure) and i can not get it off….
    but when i left of the metal lid, there is some standing water and it smells. what to do? can you email me and i will take pics and show…

  38. Reuben Saltzman
    November 2, 2011, 2:58 pm

    Clint – my email address is

  39. Clay
    November 3, 2011, 8:00 am

    We have a partially clogged cast iron 5 inch trap that carries runnoff from the roof of a 4 unti coop. The plumber is suggesting we change the trap. We suspect the trap only needs cleaning out and doesn’t need replacing. I can’t tell the age of the pipe but we know the building was gutted/renovated in the early/mid 80s. Is changing the trap really necessary for a pipe that isn’t that old? They seems to be not even bothering with an attempted cleanout (more $$ for the plumber part of the job). How does one evaluate whether to clean out the trap vs replace it?

  40. Reuben Saltzman
    November 3, 2011, 1:38 pm

    Clay – I would certainly try cleaning out the trap before replacing it. I don’t know why you would need to change the trap out. You should ask your plumber why they’re recommending that.

  41. Aida
    November 6, 2011, 10:56 am

    Hi Reuben,

    I am in the process of buying home in Bloomington, Mn and one of the homes that I am really interested in has no clean out plug in floor drain. Reading some of your previous posts, sounds like replacing a clean out plug is a coslty fix. Can you run an estimate for me? Thank you in advance and God bless you for sharing your skills and knowledge!!

  42. Reuben Saltzman
    November 7, 2011, 4:46 am

    Hi Aida,

    Most of the time, replacing a missing cleanout plug is a quick and easy repair. The replacement cleanout plug that I showed sells for about $5, doesn’t take any tools to install, and takes about one minute to pop in and secure. Good luck.

    – Reuben

  43. BCG
    November 8, 2011, 6:37 pm

    When the water in the trap portion of your drain evaporates, this removes the natural water seal and opens your home to disease carrying bugs and sewage gas smell. H2GOFlo and the the Interceptor-Plus replenishes this water periodically, creating the required barrier, that blocks off the back flow from the sewer system from having direct access into your home.

  44. Becky
    November 11, 2011, 12:31 am

    Hi Reuben,
    I have a floor drain in the basement laundry room. It is not draining. I know this because when replacing the hot water tank, the guys tried to drain it into the floor, and it wouldn’t drain. They told me it is serious and I should snake it out.
    I can’t snake it, because in my 44 yr. old house, the drain is cemented in the floor. What to do?

  45. Reuben Saltzman
    November 11, 2011, 4:33 am

    Hi Becky,

    Here in Minnesota, floor drains are always cemented in to the floor, regardless of age. The cleanout plug is there so the drain can be snaked out. I suggest you hire a drain cleaning company to snake out the floor drain. If the drain can’t be snaked out, your options would be to live with a clogged floor drain or have the drain replaced.

    – Reuben

  46. Stephanie
    November 15, 2011, 4:55 pm

    Hi. I recently purchased a home. The floor drain has clean water sitting in it. Both drain holes are open without plugs. The p-trap part has visible water standing in it and all new water exits to the side which I believe is the bypass.

  47. Reuben Saltzman
    November 16, 2011, 9:00 pm

    Stephanie – you should install a cleanout plug at the cleanout hole.

  48. Tom
    November 27, 2011, 10:49 am

    Reuben you are the best! Just wanted to say thanks for the pictures and advice on this web page. If it wasn’t for finding this information, I would have dug up the floor drain with my bare hands out of frustration. Finding the cleanout plug under the dryer and groping in the standing water for the cleanout hole, I was able to snake it out to the main and now…no problems! Thanks again from SLP!

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  50. Stephanie
    December 12, 2011, 10:05 am

    Should the water be clear in a floor drain? I have a home on a slab that has a floor drain near the water heater. We have backed up through there about 9 years ago and them maybe about 6 years ago. We have had the line scoped with a camera and all they have seen is an area where the pipe is bellied (?) From time to time we see waste in there and were told it was a product of waste being caught up in the line and coming up after backing up in the past. We shop vac-d it out (PU!) and it was clear for about a month then we saw a bit more waste so I cleaned it out again. It had been about a week now. It looks ok. The water was clear when I filled it up but now has a rusty appearance. Does stuff ever gunk up in there under normal circumstances? Thanks!

  51. Reuben Saltzman
    December 12, 2011, 2:43 pm

    @Tom – I’m glad I was able to help someone local :)

  52. Reuben Saltzman
    December 12, 2011, 2:46 pm

    @Stephanie – Yes, the water should typically be clear, however, if it’s a very old drain the water will always look dirty. If the water gets dirty fairly quickly, it’s probably a good sign that you have a problem with the drain(s) in your house. Try filling up your bath tub(s) with water, pull the plugs, then go downstairs and run the water full blast at your laundry sink while the tubs are draining. If the floor drain backs up while this is happening, there’s your answer.

  53. Stephanie
    December 13, 2011, 8:27 pm

    Well, we are on a slab and don’t have a laundry tub. I had a plumber out though and he opened up the clean out in the front of the house and had me fill the tub and then we watched the clean out while it drained and the water was flowing out just the way it should. There is also no movement in the water level in the floor drain when toilets are flushed and all that. Also, the pipes are old, about 30-35 years old. It is definitely a disgusting looking rusty pipe, cast iron? I guess we will just watch it for now. The water almost has a rusty color to it.

  54. Reuben Saltzman
    December 14, 2011, 8:42 pm

    It sounds like you might just have to settle for rusty looking water in your floor drain. Probably nothing to worry about if nothing is backing.

  55. Reuben Saltzman
    December 14, 2011, 8:43 pm

    It sounds like you might just have to settle for rusty looking water in your floor drain. Probably nothing to worry about if nothing is backing up.

  56. Stephanie
    December 21, 2011, 7:38 am

    Well, by now there is stuff filling up in there,. The water went from rusty to dark blackish and there was something that was identifiably eaten about two days earlier that was visible in there. I fear we have a massive issue on our hands, the stuff is seeping in somewhere! I will follow up once it is resolved just in case you are curious of the outcome. Thanks for all of your insight!

  57. Teri
    December 22, 2011, 11:02 pm

    Hi Reuben. I have an oder in my basement, but not sure what it is. It’s either coming from the floor drain or the neighboring bathroom. I am the only one who smells it, husband does not and plummers say it’s not bad. They tell me to poor water down the drain. I do this every couple days and it helps but it comes back. It doesn’t necessarily smell like sewer but rather some sort of metalic smell or gas. I can’t stand it though, it’s so pervasive I smell it all our clothes whenever we leave our house. This problem is causing marital problems cause husband thinks it’s pyscological.

    in to my home through the basement floor drain, I believe I’ve had a couple plummets who tell me

  58. Teri
    December 22, 2011, 11:05 pm

    Sorry Rueben, hit send too early. Is sewer smell very obvious or could it smell Ike something metalic? House was built in 1958. Thanks for any input. In the meantime I guess we’ll check the plug. Thanks.

  59. Reuben Saltzman
    December 23, 2011, 7:00 am

    @Stephanie- thanks for the follow up post. I’ll be interested to hear how this turns out.

  60. Spence
    December 28, 2011, 11:55 am

    I have a floor drain in my basement that is used as a shower drain. It is draining very slowly and I have opened the cleanout and snaked it and also checked the vent and made sure it was clear. The drain has a ball in it that I think is for preventing backups but it does not let me snake out the trap if there is one. The water drains well through the cleanout but not through the drain itself. Can I remove the ball or is this my only stop for sewer gas in this type of drain.

  61. Reuben Saltzman
    January 1, 2012, 7:19 am

    Spence – yes, you can remove the ball. That ball is there to help prevent water from backing up out of the floor drain, not to prevent sewer gases from coming in.

  62. Mark
    January 21, 2012, 5:47 pm

    All of the five Drake cast-iron floor drains in basement of my recently purchased 57 year-old house are the type with the trap clean-out plug adjacent to the grate at the top of the trap rather then inside of the grate.I am having performance problems with at least three out of five of them, including the most critical one that my AC condensate, HE furnace condensate and humidifier all drain into.I have had to disable the humidifier for now until I get this one working.

    1.) The threaded trap plugs all appear to be ferrous metal rather then brass. They have what appears to be 3/4″ recessed square sockets such that there is no way to grab with a pipe-wrench (think big hex or torx socket except square shape). These surface-flush square sockets are filled with concrete which would need to be chiseled out before any tool can be applied in attempt to break them free. If I am successful in cleaning these concrete from sockets, the next challenge is just how best to break them free. I am thinking PB Blaster and then 3/4″ drive breaker bar with nothing on it but perhaps 3/4 drive extension. Is there a better tool or drive accessory for this application? Would you think applying heat with MAP gas torch would be a good idea before applying maximum brute-force. Based on the level of rust of the whole assemble these plugs appear to possibly be badly frozen. That has me thinking Plan B already, which would be to abandon attempt to open the rust-frozen concrete-filled trap plugs and instead try to go at clean-out directly through the drain inlet.

    2.) The only grate that I can readily remove at the moment (more on that below) was over one of the drains I am having performance issues with. I was able to vacuum out a good bit if sand and concrete chips. Prior to this I had a plumber here for something unrelated. He tried to snake it through the trap but failed. About this plumber, I got a home warranty as part of the house purchase deal 1.5 years ago and they are the ones that sent him. I am suspecting he use to make a living doing construction and now due to construction market collapse is trying to make it in service. My point is that just because this plumber failed does not mean that something cannot be done. But I am wondering if there is something other then a snake you can recommend for breaking through the debris in the trap and the first few feet of drain line. At that point if I cannot work a snake through the trap adequately I am considering a jetter attachment for my 2800psi, 2.7 gpm pressure washer (example, ClogHog but feel free to delete the brand name as this is not an attempt to endorse them). The appeal there is that the hose diameter is much smaller and more flexible then head of a snake. Have you had any experience with jetters? Care to comment?

    3.) Finally, can you suggest a method for removing the grates without destroying them since these are no longer in production . They are held in place with what appear to be an impossibly frozen pan-head screw. I tried PB Blaster, but this flat-head screw is standard slot so I am doubtful I can apply enough torque to break it lose before stripping the slot. Should I just drill it out? Or should I not waste my time trying to save the grate and just break it off and then try to find a suitable aftermarket replacement. They have the name BLAKE stamped into them so if you know where to obtain replacement grates that would be a decent fit that would be appreciated too.

    A final note, I am puzzled as to why drains with traps were even used on this house. I am pretty sure they do not drain into the septic system but rather are piped directly out to the creek along rear of the property. There is a pipe that drains out there. I know it could be just storm run-off but I am thinking it is grey-water too including run-off from these floor drains. Each property here has a line like this dumping into the creek so apparently that was legal and accepted practice in 1950 and early 60s. Whatever the case, most of the 5 traps are bone dry most of the time and I have no issue with sewer gas coming up through them.

    Thank you,

  63. Reuben Saltzman
    January 22, 2012, 8:06 am

    Mark – you have quite the interesting setup.

    1 – Try a huge screw extractor.
    2 – I’ve never tried a jetter. It sounds like a good plan, but I don’t know enough about this process to say yay or nay.
    3 – Again, try a screw extractor. You just drill a tiny hole in the screw, then thread the screw extractor in to it.

    As for the traps – assuming your drains go out to a creek, the traps will at least help to prevent pests from coming in to your house.

    I strongly recommend you take a bunch of photos of your floor drains and re-post your questions along with photos at . Any time I’m stumped, I post my questions there or at another private forum for home inspectors, and I always get answers to my questions. I’m sure you’ll get some great answers from people with far more experience.

    If you do post your question and photos there, please leave a comment back here so I can read everyone else’s responses on the forum.

    – Reuben

  64. Mark
    January 23, 2012, 12:41 pm

    Thanks for your prompt response Reuben!
    I managed to partially clear one of the drains with a snake directly through the intake. I was only able to feed the snake to top of the p-trap, however, at which point I believe it is deadheading up into the cleanout plug port tee’d into the top of the p-trap rather then continuing down the drain line. This suggests to me that a jetter if fed through the drain intake will do the same. Thus, if I want better results I need to focus on getting those cleanout plugs removed. I chiselled the concrete out of 3/4″ countersunk square in these 2″ recessed plugs. In the process of doing so I discovered that the plug that I thought was malleable iron is actually brass. Then I discovered the dimension of the square recess is around 13/16ths” to 7/8ths”, definitely not 3/4″. This derailed my plan for using a 3/4″ drive breaker bar. So, I researched the internet again for a solution and discovered this tool called a drum tap wrench aka cleanout plug wrench . Here is a link to an example:
    I have been told that this tool is good for inserting a new recessed plug but I have been warned to manage my expectation level about removing old plugs with it. It is my hope to succeed in removing at least one plug in tack for the purpose of matching it up to a new replacement plug. I am told in cases such as this plumbers just drill a line of holes across the face of the plug to collapse it in.Once I get one plug out without destroying it and can verify replacement plug fit, that is probably what I will need to do for the majority of those remaining. I will save the screw extractor kit for the grates… if the plug wrench won’t turn the plugs it is doubtful a large screw extractor will have any impact.
    Thanks again!

  65. Reuben Saltzman
    January 23, 2012, 1:08 pm

    Thanks for the link – I’ve never even seen such a wrench, and didn’t know there was such a thing. Good stuff.

  66. Joe
    January 25, 2012, 5:14 pm

    This is great info. I hope you can help me.

    My 1956 ranch in Milwaukee has two floor drains and two sump pump crocks. Is it possible to close off or seal one of the floor drains? If so, how? I would like to finish the basement off and am not sure what to do with the floor drain. Any advice would be welcome.


  67. Henry
    January 30, 2012, 7:05 pm

    Hello, Reuben, glad I found your blog. Learned more here then hours scouring the web. (and I am in no ways a search novice)

    I have some concerns about a house I purchased 18 months ago. I have had a bad smell coming from the basement for the past few months on and off. Cross between a sewer smell and seaweed. (If that make sense)

    I have what I thought was a total of 4 drains, but after reading here, it seams that I have two drains and two cleanout plugs?

    Here is the second drain. Not really having any problems here:
    The opening on the left is the actual pipe and the hole on the right is filled with water like a trap.
    This is where my HVAC system drains:
    This is the trap pictured on the right:

  68. Henry
    January 30, 2012, 7:13 pm

    This is the first drain and where my smell seems to be coming from:
    Same layout, but backwards as I am facing the other direction. Trap with water on the left, actual pipe on the right.
    This is the pipe:

    While taking pictures I notced the following in the pipe:
    Digging away revealed this:
    Not sure if that is a root or piece of the pipe. I cut at it with a knife, but it felt more like ceramic then wood.

    I never have any type of drainage problems or a wet basement. Just the smell. Should the holes revealing the actual pipe be sealed off with more then just a grate?

  69. Henry
    January 30, 2012, 7:17 pm

    Starting to wonder if this is the reason I am always so tired… Looking forward to your response.

  70. Reuben Saltzman
    January 30, 2012, 8:24 pm

    Hi Joe,

    The most common way of sealing off a floor drain is to fill it with concrete.

  71. Reuben Saltzman
    January 30, 2012, 8:28 pm

    Hi Henry,

    Those are some unusual drain setups. To know if you have sewer gas coming in, try filling up a nearby plumbing fixture (such as your laundry sink) with water, and then listening carefully at the floor drain to see if you can hear the water draining. If you can hear the water at the floor drain, you have an untrapped opening.

    For any drains that aren’t being regularly used, try sealing off the holes to see if the odors go away. Let me know what you find out.

    – Reuben

  72. Guy
    February 5, 2012, 3:07 pm

    Hi Reuben,

    This is a great thread! I had a plugged drain in my furnace room that was for the condensate from the heat pump and the water softener. It was plugged when i bought the house. The softener was not in use and there was some evidence that there had been water in the carpet in the past. When getting the heat pump replaced I decided to finally try to fix the floor drain. I had tried to snake it out several times in the past with a powered snake. I never got past the p-trap. It turned out the P-trap had rusted metal in it. the floor drain was almost rusted completely away and I guess it all went down the drain and clogged the trap. I ended up jack hammering up the floor and replacing the trap. Now I am at the point where I have the new pipe with gravel around it, but don’t know much about concrete or what type to use. I want to make it look as good as I can. Do you have any suggestions?

  73. Reuben Saltzman
    February 5, 2012, 4:02 pm

    Hi Guy,

    I’m no concrete expert, but I have done it. I just used the cheap 80 lb bag of concrete mix, poured it in the floor, and made it nice and smooth with a trowel, making sure that the lowest point was at the drain. It turned out looking fine, but not fantastic.

  74. Guy
    February 6, 2012, 9:40 am

    Thanks I will give it a try tonight! Hopefully I can make it look pretty good!

  75. Steve Robison
    February 6, 2012, 12:48 pm

    Dear Saltzman,
    How are you? Ok here we go: 900 sq ft house with finished basement built in 1965 Ann Arbor, MI. Basement is carpeted, no padding just utility carpet. Kitchen sink drains down the main line and the water ends up backing up into the utility sink in the laundry room right below it. Tried hand snake attached to a power drill with minimal results. BUT, my main problem is, I can’t find ANY main, floor, house drains to unscrew and clean out! My neighbor has the same house since they’re cookie cutter houses and his are in plain view sticking up above the basement floor. I looked under my stairs, in the storage room, everywhere and their just aren’t any in sight. The only thing I can think of it that they’re flush to the concrete under the carpet? I don’t mind cutting away the carpet to look for them as I THINK I know where they might be from the noise the metal drain cover makes when I step on it. Thanks for your time. –Steve Robison–

  76. Reuben Saltzman
    February 7, 2012, 5:54 am

    Steve – don’t mess around with trying to locate and open up your floor drain. The previous owner probably filled it in because it was backing up sewage, just like the utility sink is now. The difference is that you’d have sewage on your floor, not just in your sink.

    I think you should just hire a drain cleaning service to snake out your drain; they’re not that expensive.

    If you’re set on doing it yourself, go rent a professional drain auger. I’ve never had good luck with those little hand snakes attached to power drills, but the professional drain augers have always worked for me.

    – Reuben

  77. Amanda
    February 19, 2012, 9:01 pm

    This is one of the most helpful articles I have found. Thank you SO much :)

  78. GML
    February 26, 2012, 11:26 am

    I have a floor drain that seems to be running slow…usually only when the washer empties a small amount of water will back up onto the floor. Do you recommend snaking or would a flat sewer rod be as effective?

  79. Reuben Saltzman
    February 26, 2012, 11:42 am

    GML – yes, I would definitely recommend snaking the drain out. I had the same problem at my last house, and I had to snake the drain out about every two years.

  80. GML
    February 26, 2012, 11:47 am

    Thanks for the fast reply…I just did it last year and was thinking that a 50 ft sewer rod would be as effective.

  81. Henry
    February 26, 2012, 12:36 pm

    Hey Reuben,

    Wanted to give you an update on my findings from last month. My guess is someone added the openings next to the trapped drains or the drains themselves at a later point in time. The openings in the floor beside the drains with the traps are openings of the main line exiting the house to the sewer system. I have a vent and clean out plug out in the yard.

    I guess there is something wrong with the vent/trap outside as to why I am getting smell in the basement. I have since made a DIY plug for the opening and the smell has gone away. (I wasn’t getting smell from the other because someone installed a bell trap as scene in the picture.)

    But both openings could use an item I found at the hardware store called a saddleback clamp.

    Both sections just have the top part of the pipe cut off for access, there isn’t any type of T fitting. I may bust up the floor in the future and install these clamps so the pipe is sealed and has two dedicated cleanout plugs that screw in.

  82. Rebecca
    March 1, 2012, 10:15 pm

    Hi Reuben, I hope you can help with an issue I’m experiencing. I’ve found that after someone pops and flushes the toilet, a few ours later a sewer gas smell comes from my basement floor drain and then the smell travels through the heat vents throughout the house. This only happens after someone pops and flushes it. I do pour water in the drain and flush the toilets often to flush it through. Sometimes the drain does dry out even after I pour water in it. I have no water backup and everything seems to be working okay, just a bad smell that hangs around a day or so after someone pops. Any ideas?

  83. Reuben Saltzman
    March 2, 2012, 4:21 am

    Thanks for the update, Henry.

  84. Reuben Saltzman
    March 2, 2012, 4:23 am

    Rebecca – if the water in your floor drain dries out quickly, it’s probably leaking through the bottom of the floor drain. Try completely covering the drain in a temporary manner to see if that fixes your problem. For instance, try completely covering the opening with duct tape. If that fixes your odor problem, you know the issue is your floor drain.

  85. Rebecca
    March 4, 2012, 9:07 pm

    Hi Reuben, I covered the drain as you suggested and everything seemed okay till someone had to poo then the smell came back again. I see the plug in the drain and I don’t think the drain dried out. The smell will go away after it flushes through the system however it will come back again after someone goes poo again. It’s strange because the smell does not begin till a few hours after someone has gone to the bathroom. There is no backup at all and everything seems to be working fine. Do you think the plug might be bad letting the smell in or could there be a clog? I guess it might be time to call a plumber. I’m nervious to call a plumber because I don’t have expertise in this area and I won’t know if what they are telling me is correct.

    Thanks for the help Rebecca

  86. tom
    March 12, 2012, 11:04 pm

    Hi Reuben I was wanting to finish my basement but the floor drain I have is right in the center of the basement twords the front of my home next to the water line that comes into the house. The water line is close enough to the wall that I can hide it but the drain is about 3ft out from the wall where I want to lay carpet. What I want to know is would it be okay or up to code if I was to tear up the floor and tie in a new floor drain at the back of the house where the soil pipe runs down from the first floor and then just concrete over the old one ? or would this cause drainage issues ?I believe the original drain was put there because it is the closest part of the house to the street where the drain runs to the sewers. I mean is it okay to change the drain location

  87. Reuben Saltzman
    March 13, 2012, 3:52 am

    Hi Tom,

    Here in Minnesota, it’s perfectly fine to change the location of the floor drain, or even get rid of the floor drain if you want.

  88. Meghan
    April 3, 2012, 9:45 am

    Hi Reuben! When I turn on my attic fan I notice a terrible sewer smell. After doing some investigating, I found that the smell is coming from the floor drain in my basement. I poured water down the drain and the smell was a little more tolerable but I could still smell it. Someone told me to pour antifreeze down the floor drain. Is that an alright thing to do? Do you have any suggestions?

  89. Reuben Saltzman
    April 3, 2012, 9:53 am

    Hi Meghan – lots of floor drains are just plain stinky. Cleaning it with bleach might help with the odor. As far as the anti-freeze, go for it. Just use RV anti-freeze. Anti-freeze won’t evaporate.

  90. drainage experts Sonoma
    April 9, 2012, 1:53 am

    Your post can help many home owners in influencing them to know the proper way of maintaining their floor drains. This can in turn prevent further accumulation of debris that can affect the plumbing and drainage system. Thanks for sharing!

  91. Val
    April 21, 2012, 8:03 pm

    Hi Reuben

    Water from my kitchen sink is coming up the floor drain. The kitchen is directly above the furnace room where the floor drain is. When I just run water down the kitchen sink for a long time there is no problem with the drain. When I fill the sink then unplug it the larger volume of water causes the problem and floods the furnace room floor.
    Any idea what the problem might be??

  92. Reuben Saltzman
    April 23, 2012, 3:54 am

    Val – The drain line is partially clogged. You need to have it cleaned out.

    – Reuben

  93. Allison
    May 2, 2012, 7:11 am

    Hi Reuben,
    Last night the floor drain in our laundry room backed up with this black crud. It doesn’t smell like sewage, more like chlorine. When it backed up we were running a medium load of laundry. I’ve run several loads since and it hasn’t happened again. We have had a lot of rain this week, but we’ve had more in the past and never had an issue. My question is actually two fold. First is the obvious, how can I prevent it from happening again? The second is how do I get that awful chemical smell out of the clothes that got wet? I’ve soaked them over night, and washed them several times, and nothing is working. I really don’t want to have to throw them away, one pile that got wet was my husbands dress shirts. Thank you for you help!

  94. Reuben Saltzman
    May 4, 2012, 4:18 am

    Hi Allison,

    I’m stumped. Having a lot of rain shouldn’t affect your floor drain; if it does, you probably have a hole in the drain line that runs under the house, as well as a partially blocked drain line.

  95. Val
    May 5, 2012, 4:15 pm

    Thanks Ruben, you were right and I did get the line cleaned out and it is all good now.



  96. Karen
    May 14, 2012, 4:18 pm

    Hi, I am n deep trouble. We bought the home we live in 9 years ago, built in 1973, we live in rural St. Louis MO. After the first week we moved in our basement flooded, we had a plumber go o top of the house and ran a snake from the stake vented out from the roof all the way down and out to the street, the problem went away after that for a couple of years and then came back with a vengance. It flooded so bad in our basement that we had to have more than half of the floors and walls replaced, it was snaked again and I thought the problem was solved. Well that was 9 months ago and it happened again, this time we caugt it before it travled out beyond the furnance room.
    We have had the raw sewage smell when you run the sinks, and earth dirt coming out of the bathtub in the basement. I have family that is coming in town and the only place I can put them is in the basement but before they get here I want to have this problem taken care of once and for all.
    What would you suggest? I am thinking of a video scope of all drains but will that go into the P traps and show if there is any damage?
    Thank you for reading my long story.

  97. Christine
    May 17, 2012, 1:21 am

    I have a sewer clean-out with the cap in place in my family room, in a remodeled basement that smells like mildew. We purchased the house (built in 1976) and moved into it in January, it had been vacant for about 18 months. At that time the sewer backed up and we had someone out to clear the lines and haven’t had trouble since. It seems strange to me that what appears to be a sealed and closed up pipe could be a source of the mildew smell. I’ve smelled the nearby outlets thinking the smell could be coming from inside the wall, the carpet and the whole general vicinity, but it really seems to just be coming from the clean-out pipe. There is no moisture anywhere that I can detect and though we are in Washington state we live on the dry eastern side so there is no dampness to speak off. The laundry room on the other side of the wall where the small amount of flooding <1inch actually occurred smells fine. Any suggestions?

  98. Reuben Saltzman
    May 17, 2012, 3:32 am

    Karen – I would suggest doing exactly what you’re thinking. Hire someone to run a camera down the main building drain to figure out what the problem is. That won’t cover all the P-traps, but from what you’re telling me, it sounds like you have a problem with your main building drain.

  99. shawn
    May 19, 2012, 6:41 pm

    Hi thanks for the info! My basement floor drain has been stinking. My drain goes straight down which i guess is the trap. It holds water. Then above it i have a random line coming into the drain and directly across from it one line exiting. From the sound of it it sounds like the outgoing line would be a cleanout and should be plugged. I dont want water to back up into the incoming side of the pipe. When i fill the drain it comes up to the higher lines and stays there. Then the water slowly drains to just a bit in the trap. What can i do to stop the smell?

  100. Reuben Saltzman
    May 20, 2012, 5:54 am

    Christine – no, I don’t have any great suggestions for you.

    Shawn – what you’re describing sounds like a missing cleanout plug. Can you send me a photo?

  101. Nanette
    June 11, 2012, 2:30 pm

    How important are basement floor drains?
    My husband and I added a bathroom to the basement of our 1930 bungalow a couple of years ago. At the time, we discovered the nearest floor drain was non-functioning and without a P-trap and I couldn’t convince hubby to replace it. (He had already done the concrete busting/digging/hauling, not including that section and a plumber installed the new lines, cutting off and bypassing the old drain before hubby laid new concrete).
    Recently, we had to install drain tiles and a sump pump and had the workers cut open the old floor drain while they were at it. The washer and dryer are now located next to that floor drain, and if the washer ever overflowed or there were bathroom or other flooding issues, the water would have no place to go.
    We are finding it challenging to connect a new floor drain in that location to tie into the existing drains, which accommodate basement shower, kitchen sink and dishwasher (upstairs), as well as the clothes washer. These all come down vertically through the wall behind the washer and dryer, except for the shower on the other side of the wall, which connects in horizontally, closer to the main soil stack. At present, all fixtures include traps and vents, are to code and passed inspection.
    The horizontal drain pipes run the opposite direction…not under the washer, toward the floor drain, but under the bathroom floor toward the soil stack and sewer line which runs out the back (west end) of the house toward the alley. There is an elbow where we need to tie in (from vertical to horizontal). The floor drain would be at the farthest point from the sewer main in the basement plumbing drainage system (Since hubby didn’t want it, plumber didn’t account for future installment when adjusting slope of drain pipes from washer, etc.)
    There is a floor drain on the back end of the house, but the floor is poured separately there, offset up about 1/2 to 3/4″, then sloping toward the drain in the northwest quarter. The bathroom is in the middle of the south side of the basement. The floor drain we have dug out is about 3-feet from the bathroom door, closer to the east/front end of the house.
    Is it worth the trouble to tie in the floor drain, insuring proper slope, trap, etc? Or are we being paranoid about the need for it? During the remodel project, our clay tile sewer line busted out in the alley (probably from trash truck traffic) and that floor drain backed up while it was still connected, plus the one on the west end. The flooding which caused us to put in drain tile was from heavy rain which seeped up through cracks in the concrete floor under the carpet on the east end, but it subsided before it ever made it as far as the drain location would be (carpet was ruined).
    So we have a history of water problems, but will we make it worse by giving the sewer a place to back up into, or make things worse by not having a place from water to drain from in the event of flooding? (Sewer line was fixed at our expense, but we’re at a point of needing to snake again).

  102. Reuben Saltzman
    June 14, 2012, 7:09 pm

    Nanette – I think you’re mostly being paranoid about needing the floor drain. If I were you, I wouldn’t put one in.

  103. Susan Kennedy
    June 24, 2012, 1:33 pm

    Hi. Have just began experiencing slight leaking from the drain line off the furnace/ac unit. The leak is occurring right above the concrete flooring where the pipe is directed into the floor. The original pipe is copper. The drain pipes from the interior unit are PVC, connected/secured to the copper with proper fitting clamp. What is the best, least expensive fix? Could we use the expandable polyurethane foam to fix the leak? Obviously the only time this happens is when the ac unit is running. Thanks for any/all suggestions you can offer to fix this problem.

  104. Reuben Saltzman
    June 24, 2012, 7:10 pm

    Hi Susan,

    Please send me a photo or two of the leak, and maybe I’ll be able to recommend a repair. Expandable foam would definitely not be a good fix.

    – Reuben

  105. Leigh Spear
    June 25, 2012, 6:58 pm

    Hi Reuben-

    I live in a house built in the late 70’s. We have a 3/4 bath in our basement that badly needs remodeled. It had an alcove shower stall in it that wasn’t attached to anything. The shower drain was just set over the existing floor drain. We took it out and cleaned up the area. We never used it. I would like to put a proper shower stall in there using direct-to-stud install. My problem is the drain. It already has a p trap and a clean out. How do I tie a shower drain into it? I want this shower to go directly over it.
    Also to make things more interesting. The center of the floor drain is 17 inches from the stud wall. The kit I want to use requires 18 inches. Since the floor drain has the bigger top opening, is there some way I can move the top of the shower connection over that necessary inch?
    I hope to start work in a couple of weeks. What do I need to do?

  106. Reuben Saltzman
    June 25, 2012, 7:39 pm

    Hi Leigh,

    I’m having a tough time following. You say you had a shower drain set over the existing floor drain, and that the existing floor drain has a p-trap and cleanout… and a concrete floor, I assume? If that’s the case, you could tile right up to the floor drain.

    If you want to use a kit, you’d probably need to convert to the floor drain to a proper shower drain, which would involve breaking up the concrete floor and completely re-doing the drain.

    – Reuben

  107. Dave
    June 28, 2012, 11:18 pm


    Great blog / info.

    My basement floor drain needs replacing, and I’m debating doing it myself vs. hiring a plumber. (Yes, I’m capable, but I’m getting the feeling that specific experience with this task is best for taking this on.)

    You mention a couple of times in this thread that replacing the floor drain is expensive. I’m getting the hint that you purposely haven’t noted a number, but I’m gonna ask anyway. What can one expect to pay an experienced plumber to do this job?

    I’m in Colorado, but Minneapolis numbers would be just fine. I’m just trying to get a ballpark number for thinkin’ purposes.

    Please let me know if you need further info about my situation, and thanks for any help you can provide.

  108. Reuben Saltzman
    June 29, 2012, 4:04 am

    Hi Dave,

    I remember one plumber quoting $2,000 to replace a floor drain; not for any specific house, just as a general guideline. I think he may have been a little more expensive that most others, but replacing a basement floor drain is a long process.

    Break up the concrete floor, dig out the dirt around the drain, cut out the drain, install the new one, backfill for proper support, mix up and pour new concrete for the floor, clean everything up when done… it’s a fairly involved project.

  109. Dave
    June 29, 2012, 12:44 pm


    Ouch! Thinkin’ that hard hurts. But, that’s what I needed to know.

    Now I think I’ll think some more.

    Thanks for your help.

  110. charles
    July 5, 2012, 6:55 am

    i have a broke drain line under slab in kitchen pipe is cast iron would you do a bypass i think if i break slab i will find more than broke pipe beleve the whole pipe is bad slab is craked gas and water cumming up through floor i live in north louisiana

  111. Kellie
    July 6, 2012, 1:03 pm

    I have a floor drain that is backing up whenever we flush the toilet, drain dishwater, run the shower and especiallly running the washer…the washing machine drain pipe is not routed into the main drain, rather the drain pipe is set up to empty directly into the floor drain. I think that the main drainpipe in the house is clogged somewhere after where the floor drain links in because everything is backing up out of the floor drain. I had a similar problem back in Decemer; it was suspected at that time that a main pipe was collapsed so I had a camera scope done. No collapse at all, they said the main pipe going out to the sewer was in good shape. I suspect that the main drain is clogged again; the local hardware store rents out large plumbing snakes. Do you think that snaking will work? And how do I get the water out of the basement? It was suggested that once the drain is snaked out and draining properly, wait for the standing water to drain and make sure that the “crud” in the basement from it backing up is kept away from the drain to let the water go down, then once the water itself drains, clean up the sludge with shovels and buckets/heavy duty trash bags and disposed of, then scrub the entire basement floor with bleach to prevent molding. Opinions or advice? I would also like to add that I am on a severely restricted budget….

  112. Reuben Saltzman
    July 7, 2012, 5:59 am

    Hi Kellie,

    As long as you rent a large enough snake, that will probably work. As for getting water out of the basement, once the clog has been taken care of, it should all drain back down the floor drain. The rest of your ideas for cleaning up are right on.

    – Reuben

  113. Reuben Saltzman
    July 7, 2012, 6:00 am

    Charles – I think you should hire a professional to fix it.

  114. Heather Tomi
    July 12, 2012, 4:00 pm

    We are having a house built and are having them put a corner shower in the garage. The garage was suppose to be 21′ deep flat surface. Instead it is 19′ deep flat then a 4″ elevated area that makes up the other 2′ of depth. The builder is telling us the shower had to be elevated for the P trap to be installed. I think the guys who did the foundation added the extra 2′ to the inside of the home instead of the garage and when the framers framed correctly it left the elevated area. The elevated area is right where the footer is poured and the builder said if we wanted the elevated area cut out he could do that, he planned on doing it anyway. Who would lay a concrete footer and plan to cut it out? There are several other errors in the plumbing/framing and I have a feeling the builder is just telling us this so he doesnt have to redo it. Your thoughts please? Many Thanks!

  115. Reuben Saltzman
    July 12, 2012, 7:43 pm

    Hi Heather – based on what you’re telling me, it sounds to me like this didn’t go as planned. Has the concrete been poured? If so, why wouldn’t they put in the drain before pouring the concrete?

  116. Heather Tomi
    July 13, 2012, 7:44 am

    Hi Reuben. Thanks for answering. Yes the concrete has been poured. There is a drain in place approximately 4 feet from the back garage wall 2 feet away from the elevated area. I have pictures of when it was just rock of the drail but there is rock covering it and I cannot tell whether or not the P trap is there. My guess is that it is because the plumber thought he was putting it in the right place. The foundation guys just forgot to push the concrete footer and concrete block wall along the back of the garage 2 feet back like they were suppose to and now the builder is trying to cover it up. I am just unsure how to prove it? We love the house and want to keep it but just want them to fix it or make some concessions for the mistakes that were made. Any further advice? Many Thanks!!!!

  117. Reuben Saltzman
    July 14, 2012, 5:51 am

    Heather – do you have plans/drawings that you could use to compare?

  118. Stephanie Berg
    July 19, 2012, 7:17 pm

    We bought a house 4 months ago. Started using the central air and the water hose drains into the basement floor drain. But it is completely clogged and nothing goes down. We snaked the clean out pipe that had a cap in place, water drains through that fine. But when we put that cap back on, it won’t drain through the p trap and we can’t get a snake to go down into the p trap because it’s a hard angle and there is a ball in place. Any suggestions?

  119. Reuben Saltzman
    July 20, 2012, 4:06 am

    Stephanie – I’ve never tried cleaning out a floor drain with a ball in it. I suggest you call a plumber.

    If you’re not keen on that idea, here’s my two cents: some floor drains can be taken apart so the ball can be removed, but I’m sure you already checked that. I would try destroying the ball to get it out. Again, I have no experience doing this, but I’m thinking a small torch might work well to make a hole in the ball, and from there you shouldn’t have much trouble mangling it enough to get it out. If you still can’t get the floor drain cleaned out after that, you would probably need to replace it.


  120. Michael Moore
    July 30, 2012, 7:19 am

    We bought a 1947 brick home in northwest Ohio with an unfinished basement and are nearly done working to convert one end to a guest suite, the other end to a model train room, and the middle to remain unfinished for storage and utilities. Each of these areas has a functioning floor drain, and we’re just about to put carpet down, but we’re being urged to make the drains accessible so we can put water in the trap. Reading this discussion leads me to think that using some RV antifreeze may help, but should we still have the contractor make a section of carpet removable in order to access the drains? Are there other measures you’d suggest?

  121. Diana
    July 30, 2012, 8:38 am

    Hi Reuben,
    I recently purchased a 40-yr old home that did have previous occupants. I’ve noticed a sewer smell radiating throughout the house but I’ve noticed the second story bathroom stinks the worst. Whenever I open the under sink vanity the smell is almost unbearable. I tried pouring water down the only floor drain in our basement and that didn’t seem to fix the problem so I had a plumber come by the house and they couldn’t pinpoint an exact problem but mentioned that the ventilation was not properly done and said this is why the smell is being carried up all the way to the second floor bath. I guess the basement bath and 2nd floor bath share a vent. The cost estimated was $570 to address the ventilation issue. I called another plumber for a second opinion but they said they do not give free estimates for sewer smells since it could be a host of problems but the company told me anywhere from $500 to $1000 just to do the investigation to find out where the problem is (they mentioned something about peppermint and snaking cameras down the drain, seeing if the ventilation was blocked, etc.) I have yet to check on the drain plug that is discussed in the above posts but is paying to have the ventilation fixed a good start, do you have any recommendations on things I can try on my own as well?
    Your help is greatly appreciated!

  122. Reuben Saltzman
    July 30, 2012, 3:09 pm

    Michael – if you’re going to carpet over the drains, what’s the point of having them accessible? I would just plug the drains off and carpet over them.

  123. Reuben Saltzman
    July 30, 2012, 3:12 pm

    Diana – sorry, no suggestions of things you can do on your own. I don’t blame the one plumber for saying $500 – $1000 to diagnose the problem; that’s where most of the work will probably be required. In the end, the repair might require opening up a wall or ceiling to find where the problem is located.

  124. Randy Moe
    August 11, 2012, 9:34 am

    I am in Chicago 10 year old warehouse work/live artist condo conversion. I am installing 2 large darkroom sinks. I need to drain them. Right near them is 4″ threaded clean out pipe. It goes straight down 4′ and feels like a 90 turns to the main building sewer line exit for the building. There is no up vent. I am planning to test flow with clean water. If this pipe flows good is there any reason not to drain this way? My other alternatives are not so neat. One would be to drain to the bathtub through a wall. The other is lift the water heater up 6 inches do I could drain to the existing floor drain under the water heater. And again need to punch a wall. I did a lot of process water plumbing in a factory where we simply put our warm water down a similar open pipe. When I opened the condo floor drain it was dry to the bottom and no smell. Any thoughts?

  125. Reuben Saltzman
    August 12, 2012, 6:41 am

    Hi Randy,

    That 4″ cleanout is probably for the main building drain. If there were ever any issues with the main building drain, this would need to be accessible.

    Without having a separate vent, you would have the potential for water to get siphoned out of the trap(s) in your sinks, which could allow sewer gas in to the home. Nevertheless, your other options don’t sound any better. Using that 4″ cleanout opening sounds like your best option.

  126. Randy Moe
    August 12, 2012, 7:50 am

    Hi Reuben,

    Thanks for your quick reply. I agree my other options are poor. Another question is. Does each sink need it’s own p-trap?

    Regarding the main drain building access, we have been there. Just weeks after initial occupancy 10 years ago we had sewer backup issues in all units upstream of me. The original plumbers snaked and used cameras. The city tore up the street right outside my unit 3 times. Finally it was decided we needed to dig up the sewer pipe under my bedroom, now the darkroom. This was a new slab, new beautiful floor and all new plumbing. They dug down 10 feet to reach the main pipe. Upon opening the pipe they removed a 10×12 foot piece of plastic sheeting. It was stuffed into the building main sewer exit pipe. Obviously sabotage! I have pictures and lived in the unit while all this went on. As urban pioneers it was speculated the neighbors did it, or workers mad at the contractor and developer. Regardless it was a huge mess and resolved a huge problem. I should know those pipes better, but my pictures inside the hole are poor and memory worse. One ongoing issue is the plumbing documentation of existing and new pipes is non-existent. Giving work to the lowest bidder is a really bad idea. Having corrupt building inspectors is even worse. There was a major scandal at the time of this construction throughout the City of Chicago.

    We have survived many building issues. We also had to replace the”new” roof at 2 years and flat roof drainage is not ideal. This project was a conversion and combining of three 110 year old factories into one building. We will be having more special assessments.Despite all this only 2 units have turned over!

    Thanks again!

  127. Randy Moe
    August 12, 2012, 7:19 pm

    I’m back. Not good news I am afraid. The ‘clean out’ I was going to use is a dead end. I found pictures I took during construction and I see a standing pipe screwed into that clean out. It was removed before drywall and the hole in the floor today proved not to flow enough water. I think it just leaks into the dirt 4 feet down. I have no place to drain my darkroom sinks. The real kicker is all units were supposed to have utility sinks and they ‘forgot’ to install mine…

    One scenario is to install a large holding tank under the sinks, drain into them and use a pump to move the chemical water through the wall into the bathtub. The bathtub is directly against the wall the sink is on. Not a great plan, but simple.

    Plan two is to run a drain pipe through the same wall past the bathtub end and basically run around the bathroom floor perimeter until it reaches a known clean out in the adjoining kitchen. It would be a 15 foot run without a slope.

    I am running out of ideas. I want these sinks usable. This is my only available space (I own it) My retirement career requires working sinks. Digging a new drain through a the 12 inch slab and connecting to the buildings main sewer seems un-affordable and extremely disruptive to me and the other residents. Look what a mess it took the first time.

    I have pictures of the last dig correcting the sabotage and I have pictures of the areas I want to use before drywall from construction.

    Here is a link if you want to take a look. I hope the link works.

    BTW Darkroom waste water is considered safe for household drain disposal.

    Thanks for any ideas you might have.

  128. Randy Moe
    August 14, 2012, 4:02 pm

    Another update. I ran a hose from my sink to a 3/4 PVC pipe that comes up from my floor drain under the water heater. They installed the water heater so tight and on top of the floor drain I doubted it’s existence. My doubt stems from AC condensation dripping on the area. I just assumed the floor drain did not work. The drain does flow very well. I had a garden hose at full pressure draining down there for a couple hours. The AC condensation pipe was simply badly connected. My new plan is to use this 3/4 PVC tee as a darkroom sink drain. The floor drain is not sealed and the supply pipe has a 4 foot vent pipe. This seems the better solution than my prior plans.

    I checked with some photo forums and many people are using a sump pump in a bucket to pump the sink water somewhere else.

    Water usage does not need to be extravagant in a darkroom. The chemicals are mixed at low concentrations that many people can tolerate on their skin. The majority of water usage is running clean water over film or paper to remove chemical traces. This can be very low total volume and lasts for 10 60 60 minutes.

    Now I need to find some money for temp control of my water supply. Intellifaucet is one method I may try.70 degrees is the ideal temp.

    Thanks Reuben for a wonderful site and blog.

    BTW I was born and raised in Minneapolis, but we moved when I was little. I have fond memories of Minnesota.

    Thanks again!

  129. Reuben Saltzman
    August 15, 2012, 4:05 am

    Randy – thanks for posting the updates on your project. I tried viewing the photos you linked to, but Google said “403. That’s an error.
    We’re sorry, but you do not have access to this page. That’s all we know.”

    I’m glad to hear you found a solution without having to break up your floor.

  130. Stinky Plumbing Fixtures | Structure Tech Home Inspections
    August 21, 2012, 4:52 am

    [...] have their own built in traps, and so do floor drains.  The trap on a floor drain is located below the surface of the floor – the photo below [...]

  131. Terry Akers
    August 25, 2012, 2:45 pm

    Rueben: My problem is similar to many of the posts here. However, my floor drain is a condensate drain that has two air conditioner condensate lines draining into it. The drain is PVC piping and stands up approximately 1.5 feet off the slab. There is no drain plub. House is 20 years old and for the first time this drain is over flowing. I know a condensation pump would solve my problem but have never needed one before. What are your suggestions about unstopping this type of drain? Thank you for your time and assistance.

  132. Reuben Saltzman
    August 28, 2012, 3:43 am

    Hi Terry, is there a trap in the pipe above the floor? If not, I’ve never seen a drain like that. My suggestion would be to try the standard drain cleaning methods – ie, try starting with a small snake.

  133. Terry Akers
    August 28, 2012, 7:57 am

    Reuben: I used a shop vac to suction out the standing water and could see a bend in the pvc pipe at the bottom (there is no trap). I originally thought the drain went to a gravel bed below it but the pipe appears to go toward the footing. Used a snake and it did take care of the problem. Thank you for your response.

  134. Trent
    August 28, 2012, 11:22 am

    Good afternoon Reuben,

    I am a first time home buyer who just purchased an 83 year old house that has a floor drain in the basement (that ties into the sewer line). The basement has slightly flooded once leaving the carpet saturdated and I have observed it closly since, I have noticed the flooding occurs when it rains or when washing machine, shower, or dishwasher are running and water in basement does not take to the drain (from dehumidifer and/or All-Dry system). The flooding has always been of clean water without smell. So I cannot figure out if the water is from my washer and shower backing up, water outside of home backing up (possible storm system?), or dehumidifier/all-dry not draining (bc other water exiting or water backing up?). I have tried snaking the drain and all clear. My first question, is what do you think is happening? And do you think it would be best to install sump pump and somehow connect with floor drain so when it overflows I can pump it outside the house? Or should I get my drain video inspected and accessed by a professional?

  135. Reuben Saltzman
    August 28, 2012, 2:38 pm

    Trent – your first step should be to have the main drain line video scoped to figure out where the additional water is coming from. Rainwater shouldn’t be interfering with the main building drain.

  136. Ryan
    August 30, 2012, 12:00 pm

    Hi Reuben,

    I moved into a new condo about 3 years ago. There was a strange smell coming from my laundry closet, which only consists of a stackable washer/dryer. I had first thought the washing machine was the reason for the sewer odor, but a repairmen said that there was no p trap. So basically the only way to solve this issue has been to pur mineral oil down the drain (underneath the w/d and very hard to get to) every couple months which does actually erase the smell. Is there a permenant solution and is there a “normal” estimated cost that you could provide. Thanks so much for your help1

  137. Reuben Saltzman
    August 30, 2012, 2:11 pm

    Hi Ryan, the repair is to have a plumber install a trap. There is no type of ‘normal’ estimated cost for this, because each situation can be very different.

  138. Patrick Pihana
    September 8, 2012, 7:45 pm

    Great article. Most instructions for cleaning out floor drains mention removing the cleanout plug and the p-trap which is hard to visualize for a floor drain. Your accompanying photos cleared up my questions immediately.
    Great site – many thanks for the professional postings.

  139. Jack
    September 9, 2012, 9:31 pm

    Hi Reuben, a quick question:

    In the basement floor of an old building in which I work, there is a broken concrete cap over a drain. The cap is loose and can be simply lifted up. The drain itself is plugged up with old newspaper. The air in the surrounding area has a strange funk to it, and if you get close to the floor, there is a strong odor originating from the drain.

    Is this simply a trap that has dried out over time, and a poor job done sealing off the drain itself? What is the proper way to seal off such a drain?

    Should I be concerned about prolonged exposure to this environment?

    Thanks so much,

  140. Reuben Saltzman
    September 10, 2012, 3:47 am

    Hi Jack,

    It’s tough to say exactly what the issue is without seeing the drain. Yes, you should be concerned about prolonged exposure to that environment if sewer gases are coming in. Sewer gases are unhealthy.

    Does any water flow to the drain? Would it hurt for you to plug the drain off?

  141. jennifer g
    September 10, 2012, 10:35 pm

    I have a 116 yr old house I didn’t know I was missing a drain plug in the floor drain ..hole measured 2 inches so i bought a 2 inch rubber expandable plug with he wing nut I was looking for the tapered one but no one carried it ..2 inch was too big and the 1 and 1/2 was too small ..took a grinder to the bottom meteal of the rubber to reduce the diameter ,used the ground down bottom metal disk on my 1and 1/2 inch rubber with the 2 inch topper metal disk with stopper . I was one of them too big and too small projects we shopped 3 hard ware stores just to come up with a solution to the missing clean out drain plug to a 116 yr old house with a pea trap that worked lol but out of frustration imagination worked to our goldilocks. we had a rag stuck in the hole for a while but I was worried about it falling apart til i read off your website it really needed a plug the ,I didn’t know that. Thanks:)

  142. jennifer g
    September 10, 2012, 10:49 pm

    needless to say the smell is gone from the house and we ran a hose from our wash sink for half hour it drained like a champ go figure hubby is a real good house fixer upper when it comes to me complaining about thing like this lol juat think I was trying to find a cork for the hole:D the smell was so bad even my vent clip ons where keeping up.

  143. jennifer g
    September 10, 2012, 10:50 pm

    weren’t not where’ I think I need to get to sleep:)

  144. Peter K
    September 11, 2012, 2:53 pm

    Hi Reuben,
    I have a question about a 1.5 inch floor drain in the concrete slab on the bottom froor of my townhouse in Maryland. It is used exclusively to drain condensate from the A/C. It has backed up and water from the drain and condensate caused the area to get soaked. Two plumbers attempted to clear it out with 25 and 50 foot snakes, without success. The second one told me he could send someone to put a camera down there to find the problem and it would cost $500. Would it be ok to simply seal up the drain line with a plug and instead install a pump to drain the condensat eelsewhere?


  145. Reuben Saltzman
    September 12, 2012, 3:57 am

    Peter K – $500 to run a camera down the drain? That’s extremely expensive. I would call around to see if that price is in line with what other plumbers in the area charge.

    At any rate, plugging this drain off and using a condensate pump would be a perfectly acceptable repair.

  146. Vincent Ferraccioli
    September 12, 2012, 9:44 am

    I have a floor drain at the bottom of the stairs in our basement. It doesn’t drain anywhere. Originally, our house was on a septic system. House was built in 1940. The village put in a sewer system to our house (prior to our owning it) around 1970. The basement has another floor drain in the opposite corner. I have heard water running in that drain many times if I put my ear to it. Is that drain supposed to be tied to the problem drain (which is diagonally opposite from the corner drain). There is also a clean-out flush mounted in the floor about 1-1/2′ from to the problem drain. When there is a heavy rain, the first place water enters is around this clean-out. The floor has evidence that work was done in this area. Is it possible that concrete got into this drain or the pipe that might be routed under slab to the opposite corner drain was damaged or blocked? Help!

  147. Nicky
    September 12, 2012, 3:48 pm

    Hi Reuben,
    I am pretty sure no one has ever had an issue like mine but I had a shower in the basement and the shower base cracked so I was planning on replacing it but while uninstalling the shower base the drain pipe broke off from the connection it had to the main drain and there were some loose gravel around the main drain pipe which fell in the drain. Now from your experience, is there any way to remove the loose gravel, or reading from some of the post, could snake work for it? I have tried to scooping it out and using some things, and gravel comes up but falls right back in. Sorry I am a bit clueless here.

  148. Reuben Saltzman
    September 12, 2012, 6:52 pm

    Nicky – sure. Use a powerful wet/dry vac. That’ll suck it right out.

  149. Reuben Saltzman
    September 14, 2012, 3:58 am

    Vincent – that’s a unique setup you have. I wish I could give you some advice, but all I could do is guess. You would do well to hire a plumber to take a look at it.

  150. Nick
    September 20, 2012, 9:04 am

    Great forums and amazing response times! Glad to see you’re willing to give up your time to help people out so much!

    Anyways my problem: I noticed a smell yesterday and isolated it to the drain in the middle of the basement floor. Normally I could get rid of it by pouring a gallon or so of water into the drain understanding that it has dried out. This time I did that and within 5 minutes it was drained low in the trap (just at the bottom of the U). Poured more water and same thing. Then I had the idea to blast water from a hose into the trap and saw some pretty gross murky water that eventually went clear as it was pushed out of the line. Again the water drained fairly low and the smell returned. I’m thinking there is a crack somewhere in the trap but am not 100% sure. Any other culprits? If it is a crack, could there be an easier fix besides tearing the whole thing out? Thanks for the help!

  151. Reuben Saltzman
    September 20, 2012, 7:19 pm

    Nick – your issue definitely sounds like a cracked or rusted out trap. I’m not aware of any fix other than tearing the whole thing out. Bummer.

  152. Jane
    September 26, 2012, 5:31 pm

    What a find this site is! I have scrolled through your replies but was unable to find an answer to this question. I am in central MN lakes area and am thinking about finishing the basement. There is a drain right in the middle of the floor. Can you finish a floor over the drain or how does the drain function under the floor without causing mold problems?

  153. Reuben Saltzman
    September 26, 2012, 6:27 pm

    Jane – the purpose of the floor drain is to receive surface water in the basement. If you’re going to finish the basement floor with something like tile, just leave the drain there. If you’re going to use carpet, you should have the drain capped off. If you don’t cap the drain off, the water will eventually evaporate and you’ll get sewer gas coming in.

  154. Tracie
    September 29, 2012, 3:19 pm

    I bought a 1950s ranch two years ago. The basement already had a completed bathroom with toilet, sink, and combo bath and shower. The bathroom is sandwiched between the laundry room and a room that has a sewer with a cover on it. When my tenants moved in they noticed a sewer gas smell from the sewer room next to the bathroom. The smell gets worse the more the bathroom or laundry room is used as well as when the weather is warmer. I had a plumber take a look and he said that when the basement bathroom was put in it wasn’t done right. He said the bathroom is going into the sewer on the floor instead of the sewer that goes out of the house like the upstairs bathroom. He said the best way to fix the problem would be to eliminate anything going into the sewer in the floor and redirect everything to the other point that goes outside. He would also have to connect to the existing plumbing vent. He said he would then cover up the floor sewer opening by covering it with concrete. Does this sound correct?Thanks for any help. Tracie

  155. Reuben Saltzman
    September 30, 2012, 7:40 pm

    Hi Tracie – the only part I’m not clear on is “sewer”. If you replace “sewer” with “floor drain” in most of the places where you say sewer, this makes perfect sense and your plumber’s recommendation sounds correct.

  156. Tony
    October 5, 2012, 7:35 pm

    Hello Reuben, My bath tub is draining really slow, I tried using a plunger and it still the same. So I went to the light well which is an open space for fresh air where the floor drain is located, I used one of those Drain bladder to try to clear out the drain and all of a sudden water and lots of water and sand was coming up from the drain! I don’t know where the sand came from. The rain gutter is also connected on the same floor drain. Please help!! Thank You in advance.

  157. Anna
    October 9, 2012, 8:08 am


    Seven years ago we moved into a brand new bi-level home. Within a month the main drain had backed into our home and all over the brand new finished basement. We had a plumber come out who cleared the drain stating the clog was a white paste possible paint from new construction.

    Now we are new to the owning a house ordeal and everything as far as maintenance is new to us. We have leavened to maintain our home through trial and error.

    Yesterday we were leaving to celebrate my bday and again the sewer had backed into the house again causing major damage to our finished basement. My husband said the clog was in the trap and he was able to push that through. He did use an old auger my dad had laying around.

    My question is four fold.

    1) If he pushed the clog thru with a 25 foot auger do I need to be concerned that it can possible clog the main drain? Should I call a licensed Plumber out?

    2) Obviously I do not care to remodel my basement yet again after this remodel. Is it possible that one of these backwater valves I have seen here on the internet would help with this?

    3) Now this may sound silly but we quit using the expensive soft plush Charmin the first time this happened because we were not sure if this was the issue. Recently we went back to using this nice soft thick tissue. A month later woolah we have a flood. Can this expensive plush toilet paper be the cause?

    4) Do we need to have our drains inspevted annually like we do our HVAC system?

    Thanks so much


  158. Kimberly
    October 9, 2012, 12:28 pm

    Seems like lots of knowledge here, so maybe someone can answer my question regarding a 1946-built Freddie Mac “as is” foreclosure I am hoping to buy. I’ve had the house inspected and the inspector suggested I get the sewer line videoed so I’ll know if the sewer lines are in good shape or need to be replaced. Had that done today, only the camera could only go from the main clean-out near the back of the house, to the trap buried in concrete near the front of the house. There were two caps at floor level indicting the trap near the front. The plumber said to view the rest of the sewer the trap would have to be jackhammered out of the concrete and replaced with a regular line. He said they used to build houses with a main house trap, then discovered they didn’t need them because the traps for each drain took care of the sewer gas problem. He further said when they encounter these old traps, they remove them and replace with straight piping. My question is: Is there really no way to view the sewer pipes leading out of the house? I currently have no way of knowing if the pipe is in good shape or needs to be replaced and can’t afford a 10K+ expense if that’s the case. I will add that the former homeowner did report slow drainage, but no backups. The plumber said the slow drainage is due to the existence of the house trap, and possibly roots in the pipe outside the house, but said there is also no way to clear the line as long as the house trap is there. Is this all correct? Do I have to live with slow drains due to the house trap or pay 3K to have it replaced so the rest of the line from the house to the street can be viewed and/or cleared?

  159. Reuben Saltzman
    October 9, 2012, 1:56 pm

    Tony – wow, sand coming up out of the drain? I think you need to hire a plumber to figure out the problem. This goes beyond the scope of anything I could diagnose.

  160. Reuben Saltzman
    October 9, 2012, 2:02 pm

    Anna – #1: probably not. The main drain will be much larger.
    #2: Possible, but very unlikely. I’ve seen those things leak like crazy. The only work well when they’re brand new.
    #3: Good question. I haven’t done any type of research on different toilet papers and clogs, but I’d say that if this had anything to do with the clog, you have a much bigger problem than just the brand of toilet paper.
    #4: No, you don’t need to have your drains inspected annually, but it would be a good idea to have it inspected if you haven’t already had that done. Have a plumber or drain cleaning company scan your drain lines with a fiber optic camera to figure out why it keeps backing up. The situation you’re describing makes me think there is a serious problem with your drains.

  161. Reuben Saltzman
    October 9, 2012, 2:48 pm

    Hi Kimberly – I’ve never even heard of a house having a trap before going out to the street. That’s certainly not to say they don’t exist, but this gets beyond the scope of what I encounter during a home inspection.

    I would be included to believe your plumber. If it were me and I wanted the house, I’d probably pay the 3K to have the trap removed and the main drain line viewed / cleared.

    Where is this house located?

  162. Kimberly
    October 9, 2012, 3:16 pm

    The house is in Farmington, Michigan. Per the conditions of buying a Freddie Mac foreclosure, I am specifically prohibited from doing any repairs prior to closing on the house, so even if I wanted to spend 3K now to determine if the sewer pipes outside the house need to be replaced, I cannot until the sale closes. The plumber said some houses built prior to the 1950’s included a trap like this. The thinking was a trap for the whole house served the same purpose as traps on drains, however it was later learned they only slow down the flow of water and are unnecessary due to traps on each drain taking care of the sewer gas problem. My concern is not the slow drains, but whether or not the main sewer pipe outside the house will need to be replaced. That’s much more than a 3K job and I’ll want to renegotiate the price if that’s the case.

  163. tom
    October 15, 2012, 6:04 pm

    Hi ruben here’s the deal I am finishing my basement here in st.paul park however my current floor drain is located right in the middle of where I want my carpeted floor so my plan is to tear up the floor and relocate it in what I will be makeing the laundry room. My question is if and when I put in the new trap since it is further away from the sewer then before will I need to have it run at a slight angle to help flow or can it just lay under the cement level ? Cause I have noticed that the current drain don’t have a slight angle/runoff to the sewer thanks

  164. Reuben Saltzman
    October 15, 2012, 6:13 pm

    Hi Tom,

    Yes, your new drain should slope at least 1/4″ per foot.

  165. mark
    October 17, 2012, 9:01 pm


    I live in a 1920’s house and we are struggling with a terrible sewer smell. I know that its comming from the drain in the basement. I picked up the board that covers the drain and there seems to be water in there.Any ideas?


  166. Reuben Saltzman
    October 18, 2012, 3:48 am

    Mark – and there is no cleanout hole present? If there is no open cleanout hole in the drain and there is water in the trap, it’s probably not the source of your sewer odors. You could always try cleaning the drain opening, of course.

    This post covers some other potential sources of sewer odors

  167. Noelle Szczepanek
    October 22, 2012, 10:15 am

    I live in a house built in the early 50’s. We have a floor/clean out drain off of our den. We have had 12 years of sewer back up and high out of pocket costs to plumbers to snake our lines. This past winter it was determined there was a belly in our line extending out into the public street. The county came out and replaced that section of the sewer line and no more back ups. However 2-3 wks after they were out we started to notice sewer flies invading our living space. This issue is still continuing. The county was called back out to flush and disinfect our lines, which we were told would take care of this issue. It did not. The sewer flies are still in the house. We have poured clorox down all of our drains including the floor drain off of the den, however I have now noticed what should be just water laying in that drain appears to have taken on a different appearance. It looks like sewage and fecal material, minus the smell. I had noticed this in the past but figured it was a reaction of the clorox mixed with the water in the drain. After reading about these drains at no time should this have this appearance, am I correct? We are waiting for the plumber to come out and take a look. How would feces get there and is this the cause of the annoying flies?

  168. Stephanie
    October 22, 2012, 10:35 am

    Well, going back to my post last year in
    December, we are still having our problem of waste in our main floor drain, Sometimes it apprears to be greasy gunk and other times it appears to be toilet paper that is all broken up. Needless to say, I am completely fed up with my husbands passive attitude about this, I am assuming that we will need to break up our concrete and replace part or all of the pipe. I wanted to get your opinion about how much of the line to replace. If there is a single spot that has to be replaced is that all we should replace? My husband seems to think that we should replace the entire pipe but also says that there is no way he is paying to get this fixed. Is it necessary to replace all the piping or just the damaged spot?

  169. Stephanie
    October 22, 2012, 10:37 am

    I forgot to mention, if there is the slightest trickle of water from the ac or the humidifier running it seems to be enough to keep everything at bay and apparently normal. Not sure if I should be surprised about that.

  170. Reuben Saltzman
    October 22, 2012, 7:37 pm

    Stephanie – I don’t think you would need to replace the entire line, but your best bet would be to get the opinion of a plumber who can do a video scan of the drain. If you’re the same Stephanie who said there was a hump in the drain, that might be the only part of the drain that would need to be replaced.

  171. Reuben Saltzman
    October 22, 2012, 7:39 pm

    Noelle – sorry, but I’ve never had any experience trying to troubleshoot problems with sewer flies.

  172. Noelle Szczepanek
    October 23, 2012, 6:17 am

    ok, what about the floor drain, I am assuming you should be able to look down a floor drain and only see water and not what I am seeing, correct?

  173. Sharae
    October 29, 2012, 7:00 am

    We have sewer gases in our basement. It smells like it from the floor drain. We never smelled anything in 5 years & now water is covering the grate. It drains slow but water is constantly. The downstairs toilet would flow too much before settling and the sink would go “bloop, bloop, gurgle”, but only if the upstairs bath was used at the same time. From the same company 2 plumbers were sent. The first said the sewer was backed up. The 2nd plumber came for the sewer & said the floor drain is normal but the drain trap for the toilet has to be snaked. I don’t understand how the drain trap for the 2nd toilet is related to the floor drain being resolved. Unfortunately for us to have the floor drain snaked we have to remove a very expensive custom built in cabinet. Im really confused why the floor drain wasnt addressed if you can see water sitting but never saw that in 5 years. What are your thoughts ?

  174. Reuben Saltzman
    October 30, 2012, 3:44 am

    Sharae – I also don’t understand how the drain trap for the second floor toilet could be related to a partially clogged floor drain.

  175. Mellissa
    November 9, 2012, 5:48 pm

    We have a fkoor drain in the laundry roomof our basement. The kitchen sink, washer, and dishwasher all run through this drain in the floor. the drain has been backing up when we was clothes. We recently had some rain and now there is water standing in it and it won’t go down, we have run a snake down it and its still standing what could be wrong.

  176. Reuben Saltzman
    November 9, 2012, 6:50 pm

    It sounds like you have a clog downstream. I recommend you hire a plumber to look in to it further.

  177. Derek
    November 12, 2012, 2:21 am

    I have a problem and am hoping for a bit of advice. Two days ago I noticed a large amount of water had backed up out of my basement floor drain after I had taken a shower. Eventually the water DID subside, but SLOWLY. Once the water level dropped to normal, I poked around inside the trap and found a ton of debris and sediment… sand, gravel, dirt… is this normal? I’m worried that there may be roots in the sewer line, as I have two VERY LARGE evergreen/pine trees in my front yard, near where the line would run to the city sewer/street… My question is – should I be concerned that there was a large handful of debris and sediment in the trap, or is this normal? Or is it hard to say without looking at the situation? My thought is that if a root did indeed compromise my plumbing, dirt would fill into the pipe, thus explaining what I am finding? Am I just paranoid?


  178. Reuben Saltzman
    November 12, 2012, 4:53 am

    Hi Derek,

    It’s very possible that you have a compromised drain line. You’re not being paranoid – this is a very common problem with older homes.

  179. marty
    November 25, 2012, 3:18 pm

    When the washing machine on the second floor drains, after a few minutes water comes up in the basement where the floor meets the wall. The washing machine in against the back wall of the house. I can hear and feel the water come into the dain pipe in the basement and then it comes thru about 6 inches in back of the pipe where the floor and wall meet. Does this mean the cast iron pipe in the floor is clogged and leaking? How do you determine where the leak is as the pipe runs a good distance ie 25 feet to exit at the front of the house. thanx

  180. Lori
    November 26, 2012, 10:26 pm

    Hi Rueben! I have read every (almost) post on this thread and I am hoping that you can tell me that what I am dealing is an easy, inexpensive fix…
    I am in a 45 yr old one-story slab home with a main plumbing wall located in the center of my home. The floor drain is located in my utility closet near the front of the house with the main bathroom directly behind it and the kitchen, laundry and half bath behind that. For the last year or so I have noticed that when doing laundry I can hear a gurgling sound coming from the floor drain during the spin/drain cycles. I thought it was odd but it really did not phase me as everything else worked fine and there was no water coming up from it. Within the past two weeks things have progressed to a bit worse of a situation, the floor drain overflowed during the spin/drain cycle of the wash once and the cleanout in front of my house overflowed as well. It was suggested that I buy muriatic acid and dump it in my cleanout; this posed a couple of problems – first I was uneventful in my purchase of muriatic acid as I was told at the hardware store I could not purchase it for plumbing purposes and second I cannot get the cover off of the cleanout (I believe it is cast-iron due to it being 20+ years old). So with the advice of the associate at the hardware store I purchased a concentrated lye product and put it down my my laundry drain pipe after researching the possibilities of a clog due to laundry lint. This did not correct the problem so just this weekend (two days ago) I opted to try the main line cleaner product that is made by the same company in my floor drain. Again, problem still present with only gurgling during washer spin/drain cycle. I have also noticed on rare occasion that the floor drain would gurgle upon flushing the toilet. Tonight we decided to do a load of laundry following the routine of one person at the washer during the drain cycle and one person on the floor watching the drain. What transpired at that point was completely different! While the washer drained both toilets in my home bubbled and drained and then during the final drain cycle of the washer, with toilets bubbling once again the floor drain decided to fill up and overflow. We quickly turned off the washer and proceeded to soak up the standing water as to not allow it to cause the damage seeping into other places like it did the first time and I went outside to check the cleanout, it had filled up as well and was completely covering the recessed lid. At this point I am assuming that my problem is not existing in my home plumbing but between the cleanout and the sewer. My first thought, after the laundry lint idea was maybe it was a venting issue, now I am pretty certain it is a blockage beyond my home. I am really nervous about calling a plumber as I do not have very much (nearly none) money that is available to pay for everything they will suggest I replace. I hope you can share your knowledge and expertise in this matter and help me know what route to take.

  181. Reuben Saltzman
    November 27, 2012, 5:11 am

    Lori – I think you’re right with your suspicion that this is a problem with the main building drain. Here in Minnesota, you can find someone to snake the line and do a sewer scan with a fiber-optic camera for under $200. This will tell you what you’re dealing with.

  182. Lori
    December 2, 2012, 10:06 am

    Thanks Rueben! Plumber came out 4 days ago and snaked the line, had a bit of a hard time but was persistent and finally made it through. Turns out it was a wad of roots that in the dark looks like it was a large cat when he pulled it out. He also camera-ed the line and it is clear and running beautifully now. Total cost was $185, it is such a good feeling to have piece of mind that I will not be paying for any major repairs any time soon!

  183. Reuben Saltzman
    December 5, 2012, 8:40 pm

    Marty – yes, it sounds like the pipe is leaking. I think you would need to hire a plumber to figure out where it’s leaking – I don’t have any great tips to give you to figure out exactly where it’s leaking from.

  184. Lisa
    December 7, 2012, 10:36 am

    Hey Reuben-
    I have tried to research this but found no answers.. Is there any way that my clean out or access to the main line be in my laundry room under the laundry sink? House is on a crawl space (which is dry) and everything is backing up through the laundry room floor drain (floor drain has water in it and no bypass, not that i can see anyways). We tried to snake the floor drain but couldn’t get past a certain point- called a plumber and he could not find a main line access or clean out outside and we do not know where it is or would be because we just bought the house a week ago… the plumber told us it would be $275 to snake it through the toilet since he could not find anywhere outside to do it from but if his cable/cutter got stuck doing it that way is would be $1900 to get it out via putting in an outside clean out- to which I said we will explore other options. I have looked around, did not see anything outside my house myself but found something under the laundry room sink on the inside of the house that is covered and looks like a clean out, if clean out can be metal because it is not PVC. My house is a 1950s ranch- and what I am referring to as a possible clean out is located under the laundry room sink, comes about 1-2 inches above the tile, it is pretty rusty and has a circle cap with a square in the middle of it. I have no idea where our stacks are either, I see them nowhere, but there is a short vertical PVC pipe connected to the laundry room sink (next to the potential clean out) this is the only place I see anything resembling a stack.

  185. Reuben Saltzman
    December 7, 2012, 5:46 pm

    Hi Lisa,

    What you’re referring to sounds like a cleanout. Send me a photo and I’ll tell you if I think it’s a cleanout, and I’ll post it here for anyone else to see.

  186. Mark
    December 9, 2012, 4:30 pm

    Reuben, some of your readers with older houses who cannot locate their floor drain bypasses might benefit from knowing there is a style of floor drain used in my 50s built home that has a bypass adjacent to the drain grate rather then inside of it. I am sure the design intent was for the slab to be poured such that the plugged bypass port is flush to the slab surface, i.e., exposed and readily accessible. However, in my home the six floor drains all have bypasses that were hidden (buried) under the surface until I chiseled away a thin layer of concrete to expose them. Prior to a friend tipping me off that this might be the case a plumber who could not locate the bypasses made a feeble attempt to snake through the trap. When that failed he advised that because there were no bypasses the three drains that were backing up would have to be excavated and replaced in order to correct the problem. After exposing the buried bypasses I was able to hand-snake two of the drains myself and paid a second plumber $55 to power-snake a third one. Excavation of those three drains as was recommended by the first plumber would have cost thousands. Hope this helps.

  187. Mike Schmitt
    January 1, 2013, 6:11 pm

    Hi this is my first time posting a question on a site. I have a laundry tub drain in my basement that is your basic chrome brass trap that runs straight sown into what looks like a lead line under the concrete slab. The lead has a flange type lip where the chrome ties. In . It’s leaking out at the point where they meet.

  188. Carlos Diaz
    January 6, 2013, 8:06 am

    Hi Reuben,

    Great site! I’m in the process of finishing my basement and there is a floor drain that seems to be dried out. We’ve lived in this house for over 7 years and I can’t recall ever having any leaks or floods that would call for the use of this drain. I’ve never had and odors coming out of it so is it safe to say that I can plug it up with no worries of problems coming up in the future? If so, what’s the best way to do so?

    I’m planning on putting a subfloor and laminated wood. I live in New York State, Zone 5, if that helps.

    Thanks in advance!

  189. Reuben Saltzman
    January 6, 2013, 8:46 pm

    Carlos – if it were me, I’d plug the drain. I recommend you check with your local municipal plumbing inspector for the proper way to plug it. In Minneapolis, for instance, you’re supposed to pull a permit when you plug the drain, and if I remember correctly, the inspector wants the floor drain dug out and removed, the drain plugged with a cloth or something similar, and then the stub filled with concrete.

  190. Robert
    January 8, 2013, 6:17 pm

    I have been dealing with this sewer gas problem on and off for years and although I tried to read every post I couldn’t. I feel I’m closer to a solution now more than ever so let me explain my situation. I believe everything runs through the floor drain in my basement to the main line, toilet, bathroom sink, kitchen sink, and washing machine. I’m not sure about the bathtub. These traps never dry up and theres always some type of “debris” filled dirty water sitting in them. I imagined it was the debris causing the smell but now I know its the sewer gas that you speak of. At least twice a year I have a main line back up where all the dirty water enters the basement. After looking at pictures of a P-Trap I’m not sure I even have one. Is this dirty water supposed to stand in these traps under the cleanout plugs or is everything supposed to run freely into the city sewer leaving my traps empty or almost empty? I have pics if your interested. After scrolling up I see its somethin similar to what Stephanie Dec 12, 2011 described.

  191. Reuben Saltzman
    January 9, 2013, 4:49 am

    Hi Robert,

    Nothing runs through your floor drain. When you floor drain backs up, it’s just happening because the floor drain is the lowest fixture in your home. If your floor drain was sealed off, the next lowest fixture in your home would spart spewing sewage when you had a backup.

    There should always be water in your floor drain.

  192. Irv
    January 9, 2013, 7:07 pm

    water has been overflowing from my basement sink so i decided to snake the pipes> I can see three plugs on the floor and the third closet to the street is not flushed to the floor it is angled towards 8:00. i opened the two that were flush to the floor afte chipping away at cement to expose it. i finally removed the cover and snaked it fine, but now i want to close it up and i got a rubber expansion 3 inch that is to small when stretched to its maximum and a 4 inch is to big. i measure the inside of pipe and it says 3 1/2. need help cappig this off.

  193. Reuben Saltzman
    January 11, 2013, 4:34 am

    Hi Irv, that’s an odd size. Try asking Mark the Plumber – he does a Fix-it-Friday on his facebook page, where he answers your plumbing questions every Friday. He’s the plumbing pro.

  194. Ricky
    January 20, 2013, 10:59 am

    I am a first-time homeowner and recently purchased a 1950’s N.Y. ranch with a finished basement. The good news is that I do not have water backing-up or filling the basement (although a few tiles often get stained from underneath). However, there is water entering the basement trap from the surrounding concrete. I have never seen a great deal of water in the trap, but the water line shows that it has come up 3”. A plumber recently did some work on the house and replaced one of the two plugs. The other had two holes that the previous owner had drilled into the plug itself. It appears that the holes were meant to allow the water to seep into the main line. The plumber decided not to replace this second plug. I am concerned that the holes may be allowing gas to enter the home and that the water may be a sign of future problems. He believes that rain water may be streaming in alongside the air pipe. He said that I should dig up the front of the house and re-tar the area alongside the pipes. I do see that the previous owner tarred the inside area of the air pipe, so I am not sure about this solution. The trickle is entering the trap from both sides. Therefore, I am not convinced that the cause is simply rainwater. Also, there are two dry pipes that end at the highest point of the trap just below the basement floor. The plumber didn’t know what these lines were for. Any help is much appreciated. Hopefully, the pictures are attached. Respectfully, R.


  195. Reuben Saltzman
    January 20, 2013, 2:30 pm

    Ricky – the pics didn’t come through. Feel free to email them.

  196. Reuben Saltzman
    January 21, 2013, 3:22 pm

    Hi Ricky,

    Those two white pipes at the bottom of your photo look like they’re connected to a sub-slab drainage system for rainwater. I agree, those holes in the drain plug are probably allowing sewer gas in to the home, and were probably added so rainwater would drain in to the sewer. I don’t know why you have two sewer lines; you would be better off asking someone these questions who is familiar with the way homes are built in your area.

    Here’s the photo.


  197. Marilyn
    January 24, 2013, 10:20 am

    We moved into a newly constructed home in Nov 2011 and during the winter of 2012, I noticed a smell coming from the basement floor drain, When I looked in, there appeared to be ice. I poured some water into the drain and the smell disappeared.
    Over the last year the same smell was coming from my main floor laundry rm floor drain and also again from the basement floor drain. This is a brand new house, why would I have this problem?

  198. Reuben Saltzman
    January 24, 2013, 2:46 pm

    Hi Marilyn, I’ve never heard of that happening before. Try asking Mark the Plumber – he does a Fix-it-Friday on his facebook page, where he answers your plumbing questions every Friday. He’s the plumbing pro.

  199. Robert
    January 28, 2013, 4:12 pm

    Re: 1/9 I said floor drain but I meant the two traps under the cleanout plugs. I purchased some newer cleanout plugs 3″ and the smell has disappeared. But yesterday I had a minor backup again. Removed the plugs and cleaned the area. Looked greasy with debris sticking to it causing backup.

  200. Nic
    February 5, 2013, 1:50 pm

    Hi I’m In queens ny 11420 I notice some water in my basement never seen this for 15 20 years I thought my furnace backed up waters been dark in there have some one local check every year he drain fills and makes everyone fell at ease no mention off maybe snaking my clean out mayb backed up nothing. Ok so now I see my cap clean out plug came off. I’ve been having flushing issues for a week cleared out for a week now. No cap ok so I see the rim is rusted and stuck inside and top part is ok was laying there so I need to get this rusty rim off and cap back on and cleans nyc code cause its nasty but I pushed the water to my floor pipe and it drained but water I sitting noticeably so I see gook so I plan to clean up nasty stuff and snake alittle and then snake and clean clean out plug area and get that rusty piece off then replace. Does this sound good

  201. Max
    March 19, 2013, 11:09 pm

    Hi Reuben. What a wonderful service you provide! I have a garage floor drain that doesn’t seem to drain at all in my 1969 Iowa house. The drain is a 6″ wide cast iron pipe that appears to go straight down. I stuck a metal rod down it to try to free it but it seemed like I was just shoving it into sand/gravel about 2 feet down. Should I assume that this type of drain goes right into a gravel pit or does it just drain right under my foundation? If this is indeed the type of drain I have, how do I unclog it?

  202. Reuben Saltzman
    March 20, 2013, 3:47 am

    Hi Max,

    When it comes to a floor drain in a garage, all bets are off. I have expertise to share on garage drains, sorry.

  203. Lou
    March 22, 2013, 12:20 pm

    I am having problems with 2 connected floor drains in my basement. One drain has a missing drain plug and is located in a room under my front porch, and the other drain connects to the first under or through my foundation and both then tie into the vertical downspouts on the North side of my home. Water is directed underground into the Township’s rain run off system approximately 15 feet from my home. For 18 years I’ve had no problem with these unused drain, but during the past several heavy rain storms (1″ to 2″), rainwater has backed up through the rain run off system into my cellar. After the storm the rain water slowly recedes back down the drain. Where do I start?

  204. jim
    April 20, 2013, 7:42 pm

    Hey Reuben,
    First of all thanks for all the great advise youve given to all! Im going to try to articulate this question the best i can lol.
    Ok my basement does nothave acrock witha sump pump. It does have a floor drain in which backed up last week. The “drain people” said most likely from time over time from Washer machine draining (lint,hair what ever)
    Ok, so fine… So the looking at my drain from the top down (when I remove the top piece) it looks like a bowl that in the center obviously goes into the drain area that is aprox 2′ deep in which at the bottom of that 2′ deep square pit is what im quessing starts my ptrap hole.
    My qusetion is about the “bowl” at the top of my drain assembly. I have a slop sink that drains above this floor drain, and I notice that theres always standing water in this “bowl” area. Its cast iron and has aost of rustand what not. Id think there should bedrain holes of something. Should I get a cold chisel and knock some holes in this or is it doing whatits supposed to??

  205. Reuben Saltzman
    April 20, 2013, 9:24 pm

    Hi Jim,

    Email me a photo; I’m having a hard time picturing it.

  206. Reuben Saltzman
    April 21, 2013, 5:01 am

    I wouldn’t bother messing around with the top of that drain. The small amount of water that sits there won’t hurt anything.

  207. C. Treichel
    April 24, 2013, 8:02 pm

    My problem is not smell. Periodically when we do back to back laundry loads or run a lot of water in the kitchen, it backs up in the basement floor drain. I routed it which may have cleared up the problem, but I am contemplating jamming and sealing a pvc pipe into the drain and installing a one way ball or flapper check valve at a level perhaps a foot or two above the level of the floor. (I don’t need the floor drain for any other purpose) Is this a good idea? I think the added pressure from the water in the pipes above, if there is a minor blockage, would clear the pipes.

  208. Reuben Saltzman
    April 25, 2013, 3:41 am

    @ C.Treichel – I can’t think of any problems with that.

  209. Victor
    May 28, 2013, 8:25 pm

    Reuben, A weeks ago The technician changed the water heating tank. A day before another technician hook up a hose from the water heating tank directly to the floor drain to empty the tank for about 18 hours until arrive the technician to change the water tank. Everything was ok. Now the drain is blocked and the water is dark and is a bad odor. A plumber did a video inspection of the main drain found nothing wrong, sucked water out of drain and found that it was full of mud, tired to snake the floor drain but could not clear.

    What can be wrong and what can be the next steep to fix the problem.

    Thank you ,

  210. Paul
    July 1, 2013, 12:05 pm

    Hello Reuben,
    I live in Nova Scotia, Canada in a bungalow built about 1976. We have lived here since 1978. The basement has a perimeter inside drain about 2″x2″ which drains through a basement floor drain which I can access from outside. We have rusty water in the drain and from time to time the drain totally fills up with hard brown rust. Then the drain then backs up. Is there some kind of liquid solution that would dissolve this rust? If not then what would be the best solution to this problem

  211. Reuben Saltzman
    July 1, 2013, 2:06 pm

    Paul – tough question. I recommend you post that question here:

    They do a “Fix-it-Friday” where they answer plumbing questions every Friday afternoon.

  212. Kathleen
    July 5, 2013, 1:16 pm

    I noticed a sewer-like odor coming from around one of two pipes in the floor of the concrete basement of a house built in the early 1960’s in MA. These pipes lie side by side near the furnance and are both capped. I assume one of these pipes is the floor drain. For some reason, there is a type of grease that was put around the top of both of these caps and adjoining concrete. The previous owner had a history of water backup problems. The pipe was scoped, found to be out of alignment and replaced. Before I moved into the house, it had been vacant for awhile. What do you think the causeof the gas is and the reason for the grease around the top of the pipes? Why was the drain capped instead of being open so that water could be added to the trap?

  213. Reuben Saltzman
    July 7, 2013, 5:26 am

    Kathleen – my best guess is that there is or was a fuel oil tank at the property. I don’t think those pipes have anything to do with a floor drain.

  214. Tim
    July 9, 2013, 1:33 pm

    Thanks for the website and your expertise. I live in Pittsburgh and our house was bulit in 1930. We have a “drain” hole located in the middle of our driveway near the garage. After a recent thunderstorm, I noticed that water had accumulated on top of this “drain”. I took the cover off and cleaned out sediment and water that was in this approx 3 foot deep hole. There is a several inch diameter pipe which runs into this hole (the end of the pipe is downward facing into the hole). This hole does not seem to connect to anything else. Above ground in this area we also have several leaders which drain into encased holes in the driveway and presumambly into the sewer system. One of these drains from the flat roof of our garage and recently clogged with debris that I was able to clear.
    At the same time that the outside drain hole has backed up, we are also having the tubs adjacent to the washing machine in the basement (they are also located just a few feet from the outside drain hole) backing up with blackish water. When we run the dishwasher located on the first floor directly above the tubs, the tubs back up.
    Last night we had another storm, and the tubs had black water in them. So long as it continued to rain, if I got the water level down in one of the tubs, black water would bubble up from the tub’s drain. The floor drain located near the tubs had not overflowed and as I had been emptying water from the tubs for over an hour, I got the bright (!) idea to take the floor drain cover off and use a plunger (which fit perfectly over the drain) to see if that would clear the clog. Initially the water went down in the floor drain but then came up and I then had to use a cup to keep emptying the drain. When it finally stopped raining, the drain and tubs were okay.
    Sorry for the long e-mail, but I wanted to give as much info as possible. Do you think using a snake in the floor drain will solve this problem?

  215. Reuben Saltzman
    July 9, 2013, 2:19 pm

    Hi Tim,

    No, it sounds like you have a problem with your main building drain. I’d hire a drain cleaning service to snake it out, and maybe even follow up with a video scope of the drain.

  216. Tim
    July 9, 2013, 2:32 pm

    Thanks Reuben,

    Finances are at a premium at the moment so I’m wondering if there is any way I could do this myself, perhaps with some equipment rental? If you don’t recommend that, what would be a very reasonable dollar amount I should expect to pay for this service? Thanks.

  217. Reuben Saltzman
    July 9, 2013, 2:35 pm

    I don’t recommend doing it yourself; you probably wouldn’t know what you’re looking at in the camera. You could probably get a pro to do this for under $200.

  218. Susan
    July 17, 2013, 5:17 pm

    Hi. Can you tell me–I have a condensate pipe that feeds into a drain in my concrete basement floor. There is sump pump, as the basement is below ground. Is the condensate/floor drain leading into the sump pump pit? Cannot see anything since its under the concrete and there are walls, etc and the sump pump is difficult to get to. It is very hot and my ac is making a lot of condensate but the drain is very slow and I don’t see the sump pump doing anything. I’m guessing its clogged before it gets to the sump pump. Does this make sense? Should I snake it? I can’t see where the drain in the basement floor goes. What is the best approach?

  219. Reuben Saltzman
    July 17, 2013, 5:23 pm

    The basement floor drain should drain to the sanitary sewer. If the drain is not functioning properly, try cleaning out the trap first. If that doesn’t help, try snaking it. Better yet though would be to hire a plumber to get to the bottom of it.

  220. Carol Reingold
    July 24, 2013, 12:11 pm

    Hi- I was wondering if anyone knew what our house, from 1888, has in our basement- there’s an old plug, cement, about 2.5 feet in diameter. A handyman told me that it was some kind of older drainage system that they don’t make anymore, kind of like a stream underneath. I was wondering what it might be called and how it works. Our house never has leaked during any storm. We get condensation if we don’t run the humidifier, but never if we do.

  221. Reuben Saltzman
    July 26, 2013, 3:39 am

    Carol – it might be a cistern. I’ve found a number of them under old houses in Minneapolis and Saint Paul.

  222. Jim
    August 7, 2013, 10:06 am

    Hi – Informative site with interesting discussions.

    My situation:

    I live in Eden Prairie, MN in a house that was built in 1976. We have a floor drain in the laundry room of our basement. The furnace, water heater, and humidifier all run through this drain in the floor. Recently the drain has been backing up slightly on the basement floor when we wash clothes. (washer has a drain tub) The water subsides rather quickly. There is no smell from the floor drain. I snaked the cleanout hole to no avail.

    My next thought was to snake the center hole to get at the p-trap. Interestingly the center hole of the floor drain always has a water level in it but the center hole is obstructed/sealed about 3 inches down. It appears to be some sort of buildup of material or calcification. I assume this is not normal. Any suggestions for next steps?


  223. Jim
    August 7, 2013, 10:49 am

    I forgot to mention in my previous post that the water that creates the backup on the basement floor through the floor drain comes through the cleanout hole.


  224. Reuben Saltzman
    August 7, 2013, 10:53 am

    Hi Jim, just to be clear on this issue, how do you know the floor drain is “obstructed/sealed about 3 inches down” ? Have you tried pouring a bucket of water in to the drain? I’m thinking the obstruction you’re feeling three inches down is just the bottom of the trap.

  225. Jim
    August 7, 2013, 12:02 pm


    When I suck up the water from the center hole (with a turkey baster, ha) I can get a view of the obstruction. It’s before the p-trap would begin to curve. So I really don’t think it’s the bottom of the trap. BTW it’s about 5 inches straight down not 3 as I indicated earlier. Hard to describe the obstruction. On top at least it is granular and or flaky. When I pour water down the center hole, it just spills over and drains through the cleanout hole.

    I was hesitant to try and break through the obstruction with a snake until I confirmed somehow that it shouldn’t be there. What do you think? Also, if is determined that indeed what I have is an obstruction that shouldn’t be there, maybe using a snake isn’t the best way to go about it?

  226. Reuben Saltzman
    August 7, 2013, 3:30 pm

    Jim – gotcha. It sounds like that obstruction shouldn’t be there, but at the same time, this also probably isn’t the cause of the floor drain backing up; it’s probably a problem with the drain downstream from both the floor drain and the laundry sink. Try snaking out the drain from the laundry sink instead.

  227. Jim
    August 8, 2013, 8:46 am

    I agree —- it shouldn’t be the cause of the backup.

  228. James
    August 15, 2013, 10:03 pm

    Im sorry if this may have been answered already. I researched many of the listings hoping to find an answer.

    We live in Alberta, Canada our home was built in 1980. We have had a terrible odor problem for some years. The drains were scoped for breakage and they are fine.

    The odor seams to immenate from the floor drain. The drain is a 5 inch hole with another pipe leading to it about 4 inches under level from the washer. The water in the drain smells horrible. Tonight I stuck my hands in and cleaned out alot of debris. For the sake of the comment lets call it debris cause it makes me feel better having handled 1.5 cups of it. I have never seen the drain dry so it still operates as a gas trap but the water and the debris smells horrible. When I pour hot water in it disperses out.

    I am also confused because there does not feel like there is a P trap. It bends out at 45 degree about 6-8 inches underground and appears to head straight to the sewer.

    1. What is the heavy sandy smelly debris?
    2. What can I do to stop the smell?

    Thanks you.

  229. Reuben Saltzman
    August 16, 2013, 3:42 am

    Hi James,

    My best guess is that this isn’t a floor drain at all, but a sewer cleanout hole that should normally be capped off. Some houses had traps for the entire plumbing system just before the drain left the house. If you run water from the other levels in the home, can you see water movement at this ‘floor drain’?

    I don’t know what the debris is, but my best guess on stopping the smell is to cap the hole off.

  230. Victor
    August 16, 2013, 5:27 am

    My floor drain has a bad odor. I pay Home Insurance. Can I claim or ask the Insurance to take care because this created bacteria inside my house ?

    Thank you Reuben,


  231. James
    August 16, 2013, 6:31 am

    Wow, you keep some awesome hours.

    Aside from the pipe form the clothes washer that connects to the inside of the drain underground, no other pipes cross this opening. So water from other sources does not cross this opening.

    The floor around this drain is sloped and it is located right by the hot water tank and laundry facilities.

    It is strange that it is not a standard drain (P trap)

    I will do more research. Thanks.


  232. Reuben Saltzman
    August 16, 2013, 8:50 pm

    @Victor – I’m no expert on insurance, but I highly doubt it.

  233. Daniel
    August 24, 2013, 11:55 am

    Hi Reuben, any tricks to getting the plug out? House was built in 76. Plug seems to be synthetic (plastic/rubber amalgam) my efforts with adjustable crescent wrench are wearing away corners of plug–concerned I’m gonna strip away any hopes of getting plug out. Thanks for excellent service to the community!

  234. Reuben Saltzman
    August 25, 2013, 12:09 pm

    @Daniel – try destroying the plug by using a large screw extractor.

  235. Daniel
    August 25, 2013, 1:04 pm

    On a related note, is it normal to have a ball/float inside the drain? The diagrams I’ve seen online have been accurate to my situation, including yours, but none have included a float that I assume helps keep gas from escaping?

  236. Reuben Saltzman
    August 26, 2013, 3:32 am

    Yes, it’s normal to have a ball inside newer drains. That ball will help to prevent the drain from backing up, at least when it’s new and makes a good seal. It will also help to prevent the water in the trap from evaporating.

  237. Karen Kinser
    August 29, 2013, 7:29 pm

    Reuben – searched high and low for an answer to my drain issues in the basement. Thanks to your awesome advice, I now know I have a clogged P-trap and I can (thankfully) try shaking before calling in the professionals. Your site is much appreciated!

  238. Karen Kinser
    August 29, 2013, 7:30 pm

    …that was ‘snaking’ not ’shaking’. Sorry!

  239. Marjorie Newland
    September 12, 2013, 3:15 pm

    I would greatly appreciate your advice regarding a small basement bathroom that is adjacent to the laundry. The room is a 5ft by 5ft area that has a cramped toilet, sink & shower. I removed a small panel kit style shower which just drained into an 8 inch wide floor drain that looks original to the 1958 home that set about 2 1/2 inches down into the cement floor. There is another drain under the washer in the laundry.What would be the most expedient solution to get the space to code? Should I (1) simply remove the shower fixtures and make this into a powder room w/ a small sink and toilet or ( 2) remove the sink (use the sink that is in the immediate laundry space) , move the toilet over so that it is spaced to code , and cover the walls w/ water proof panels and keep the shower fixtures,and tile the whole 5ft x 5ft area with porcelain tile? There are 2 other tub bathrooms in the home and another with a roll in shower.So another shower isn’t needed.Your insight would be super.Thanks in advance

  240. Reuben Saltzman
    September 12, 2013, 3:44 pm

    @Marjorie – I would get rid of the shower.

  241. Sam C
    September 18, 2013, 10:26 am

    Hi Reuben, I’m in central Texas and looking to lease a retail space that was formerly a salon. I’m turning it into a retail space and only need 1/4 of the drains in this place. Most of the plumbing work is strait forward to me but there are 2 big floor drains that were used at a pedicure station. They use 3″ pipe and do have traps, but they go down probably 4′ before the trap. These will not be used at all for my business and I’d like to concrete and lay flooring over them. What’s the best way to cap these? I’ve had a few suggestions just to toss a rag and/or tennis balls down there then fill with concrete. That seems like it would work but is that the ‘proper’ method? Could you see any future problems?

    The previous tenant did complain about a sewage smell and insists all the traps were filled. There are 2 studer vents that seem to be okay and one vent out through the roof. Any other common culprits for the smell?


  242. Reuben Saltzman
    September 18, 2013, 1:39 pm

    @Sam C – the rags and concrete sounds fine to me, but you should check with the municipal inspections department to see if they want a permit for the work; if so, they’ll tell you exactly how to plug the drains.

  243. Sam C
    September 18, 2013, 1:48 pm

    Thanks for the original article and quick reply! Both have been very helpful.

  244. Harry Cash
    September 26, 2013, 6:48 am

    I have a older slab home and some of the iron pipes are rusted through. How common would a floor drain with a rusted top area be that allows water under the slab? Thanks, Harry

  245. Reuben Saltzman
    September 26, 2013, 1:29 pm

    @Harry C – I don’t think that situation would be typical.

  246. Jim
    October 2, 2013, 2:25 pm

    Hi Reuben;

    I originally posted this on August 7th of this year:
    My situation:

    I live in Eden Prairie, MN in a house that was built in 1976. We have a floor drain in the laundry room of our basement. The furnace, water heater, and humidifier all run through this drain in the floor. Recently the drain has been backing up slightly on the basement floor when we wash clothes. (washer has a drain tub) The water subsides rather quickly. There is no smell from the floor drain. I snaked the cleanout hole to no avail.

    What I neglected to mention in the above note that the original backup of water was at the drain tub not the floor drain. It got to the point where I had to bail the tub so it didn’t overflow. The first step I took was indeed to snake the drain from the tub to the limit of my 25 foot snake. Result was the drain tub now drained at a normal rate with no backup into the tub. But the water did back up at the floor drain. That’s when I posted my initial memo.

    I then snaked the cleanout to the 25 foot snake limit. Water still backs up at the floor drain. Here’s what I am thinking: When I first snaked from the drain tub, I managed just to push the obstruction, whatever it was, further downstream down to the main line somewhere where it doesn’t backup to the tub anymore but not far enough to then stop the backup at the floor drain. I am guessing that maybe I need to do next is use a longer snake to see what happens. Your thoughts?

  247. Reuben Saltzman
    October 2, 2013, 2:27 pm

    Hi Jim,

    I think you’re right on with your guess. I’d rent a long snake and give it a shot.

  248. Julie Cook
    October 27, 2013, 6:18 pm

    Hello Reuben – I found your site in June of this year while looking for info for what appears to be a drain in my basement – this a home built in the 1950’s in Rochester NY. We had a very wet spring this year and there was minor flooding in my basement to clean up – this is only the 2nd year I have lived here but understand that this basement has taken on water before. Though it seems the water came in surrounding the entire perimeter of the basement there was an area at what seems to be a drain where it persisted after most of the water had been pumped out or subsided. I don’t know what the drain is – and why water came in instead of out – at this source; The water was fresh water and no smell was involved. I would like to send you pictures but am not sure how on this thread. I have considered having a sump crock installed and am advised to pour concrete down this hole to seal it off. Would you advise doing that? And can you tell what the purpose of this hole was for if not originally a drain? Also, if you do have an opportunity to view my pictures, would the area where the drain now exists be a suitable location for the sump crock to be installed? I’m so glad to see recent dates on previous comments here and hope you will be so kind as to respond to mine. Thank you Reuben.

  249. Julie B
    October 27, 2013, 8:55 pm

    Hi Reuben. I have scoured the web, and your site is the closest I’ve come to answering my problem. I’m hoping you have more insight, though. I have owned my 75 year-old home for 10 years, and annually in October the house takes on a foul, sewage gas-like odor. It comes from the basement. The floor drain does drain, and there is water in it, but it looks similar to the photos you show at the top of this page. The big difference is there does not appear to be the smaller hole to the side with the plug. It looks like the hole to the side does not exist. Why would that be and any guesses as to why this problem only exists in October?

  250. Julie B
    October 27, 2013, 9:36 pm

    I should add the drain is highly rusted and flaky. I tried to clean it to find the side hole seen above and it just seemed to crumble. Should I suck out the water standing in the drain pipe with a shop vac and see if it’s clogged with the rust crumbs?

  251. Reuben Saltzman
    October 28, 2013, 3:38 am

    @Julie C – you can email me at . You would probably be better off taking advice from professionals that have already been to your home, however.

  252. Reuben Saltzman
    October 28, 2013, 3:42 am

    @Julie B – I don’t know why you would only have this issue in October. Try taping down plastic sheeting over the floor drain with duct tape. If the smell goes away, at least you’ve correctly identified the source.

  253. Reuben Saltzman
    October 28, 2013, 3:42 am

    @Julie B – and no, don’t start by sucking the water out.

  254. Bill Thompson
    November 3, 2013, 9:38 pm

    Great article, glad you included pictures. We bought our house five years in Denver, CO. I didn’t notice that the basement floor drain was plugged, as in intentionally plugged with same type of screw as the clean out plug, and our inspector didn’t either or just didn’t tell us. It also has a clean out plug and the plug is in place. How should I proceed? Should I open it and see what happens? Or should I get a back flow adaptor, (I think that’s what it’s called.), or should I call a drain guy and have them scope it. Any insight will help.

    Thanks, Bill Thompson

  255. Reuben Saltzman
    November 4, 2013, 4:38 am

    @Bill – why not just leave it alone? Do you need a floor drain? If you do need a floor drain, open it up and try running water through it.

  256. Wendy
    November 11, 2013, 7:18 pm

    Hi, I live in a home in East Central Mn in a home that was built in 1912. I have lived in my home for the past 5 years. The previous owner was a little old lady who washed her clothes in the kitchen sink and bathed once week. I have three kids plus myself so I use the plumbing a whole lot more than she did. In the past year our floor drain in the basement has become flooded about six times. It appeared to be clean water but I could see some remains of toilet paper. It eventually went down and then the problem would disappear for a month or so but the water always went away. Tonight I did a load of laundry and when I went to switch loads I had a very large amount of water on the floor. My daughter happened to be in the bathtub and when she pulled the plug not to my surprise I now have even more water. Unlike before the water is not moving. First off I am a single mother and have very limited income. What would you suggest I try to resolve this problem. I am afraid to even flush my toilet. I should add I live in city limits and have some very large trees between my house and the street. The trees are as old as the house. I am worried I have a huge problem on my hands.

  257. Reuben Saltzman
    November 12, 2013, 4:28 am

    Hi Wendy, it sounds like your main drain line is clogged. The best advice would be to hire a drain cleaning service to clean out the drain, then perform a sewer scan with a fiber-optic camera to determine the condition of the drain. It know it sounds expensive, but you could probably get it done for under $200.

    If that’s not in the budget, rent a large drain cleaning tool and snake the drain yourself.

  258. Brandon
    December 21, 2013, 11:46 am

    Hi, Rueben I live in IL and I have a huge problem with my floor drain in my basement when I use my sink, dishwasher, and my washer they all run down the same two inch pipe till it hits the four inch pipe leaving basement. whenever those three things are going I get sewage water coming up out of floor drain.. I called a plumber out to snake it and all he did was make it flood more into my basement.. after that I called a different company and they don’t understand why its doing that. both my bathrooms and toilets work just fine you have any suggestions for me. I need help bad need my kitchen sink and washer machine back…thanks

  259. Reuben Saltzman
    December 22, 2013, 5:25 am

    @Brandon – it sounds like you have a clogged drain. You need to get a different plumber out to fix it.

  260. Cheryl Cantos
    December 28, 2013, 11:05 am

    Hi Reuben,

    I hope you can help me. Last night I noticed a puddle in the middle of the basement floor. Nothing else around was wet, just the middle of the floor. There are no water pipes above or near the puddle. I searched for a source of the water but couldn’t find anything. This morning I watched water seep through the basement floor while my son was taking a shower in the upstairs bathroom. It seemed that once the water stopped draining from the bathroom, the water stopped seeping through the floor. Does this mean I have a leak in the drain pipe that runs under the house? That sounds like would be a huge problem. (I live on Long Island, NY. The house was built in 1956. We haven’t had a lot of rain lately.)

  261. Reuben Saltzman
    December 28, 2013, 8:37 pm

    Hi Cheryl, yes, it definitely sounds like you have a leak in the drain that runs under the house.

  262. Dan
    January 5, 2014, 1:50 am

    Dan from Minneapolis.At my parents house in Brooklyn Center built in late 50’s. I used the clean out of the basement shower drain and the partly cleaned out P trap as the drain and fit a bell trap into the top of the drain.It raised the new grate up a 1/4″ but by adding floor tile to the shower base and the cement block walls it was a nice remodel and retro fit. I did have to drill and insert anchors for the new and larger grate.Would like to know your thoughts on using a bell trap in new projects and to repair the old P trap. They are easier to snake out, trap attached to grate and small objects are easily retrieved.
    Thanks Dan
    I didn’t read all posts so you might have already..

  263. Reuben Saltzman
    January 5, 2014, 7:09 am

    Hi Dan,

    I don’t have much experience with bell traps, but I do know that they’re not legal. If you’re going to remodel, I recommend you break up the floor and install a new floor drain if there’s a problem with the old one. I know it’s more work, but I’ve always found it’s worth it to do it right the first time.

  264. Reuben Saltzman
    January 5, 2014, 7:09 am

    Hi Dan,

    I don’t have much experience with bell traps, but I do know that they’re not legal. If you’re going to remodel, I recommend you break up the floor and install a new floor drain if there’s a problem with the old one. I know it’s more work, but I’ve always found it’s worth it to do it right the first time.

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