Reuben's Home Inspection Blog

Bonding CSST: Forget Code, Do It For Safety

By In CSST Bonding On August 28, 2012


If you own a newer home or you’ve recently had gas lines added to your home, there’s a good possibility that Corrugated Stainless Steel Tubing, or CSST, was used.  This is a relatively new material that is approved for the distribution of natural gas inside of homes.  The best analogy I can think of to describe this material is that CSST is to steel gas pipes what PEX is to copper tubing, or Romex® is to rigid metal conduit.

CSST needs to be bonded.  The most common issue that home inspectors find with CSST is a system that hasn’t been properly bonded.  When CSST is installed without being properly bonded to current standards, there is an increased risk for damage to the material from a nearby lightning strike.  When CSST is damaged, it can leak gas and cause an explosion and/or a fire.  To the best of my knowledge, all manufacturers of CSST began implementing specific bonding requirements around 2007.  Of course, proper bonding won’t make CSST immune to damage from a nearby lightning strike, but it will reduce the risk of damage.

What about existing installations?  Building codes have something called ‘grandfathering’.   This means that if something was installed to code, it’s still a code compliant installation today, even if the codes have changed significantly.  The nice thing about being a home inspector is that we don’t need to get hung up on code requirements.  If something is deemed unsafe due to a change in accepted residential construction standards, our Standards of Practice require us to recommend repair.

If CSST was installed to code in 2005 and the manufacturer didn’t have any special requirements for bonding at the time it was installed, the installation still meets code… but that won’t stop a home inspector from recommending the system be bonded to today’s standards.   The manufacturers of CSST have changed their installation requirements because they’ve learned that the old methods weren’t good enough.

What does proper bonding look like?  All manufacturers of CSST require the systems to be bonded in a specific manner – there needs to be a separate ground wire connected either to the rigid gas piping before the CSST, or directly to one of the CSST nuts.   The diagram below shows an example of what this would look like when properly installed to today’s standards.

Bonding CSST diagram

The photo below shows an example of CSST bonded at the exterior of the home, with the bonding clamp connected to the CSST nut.

CSST Bonded at nut

The video below, produced by Gastite, shows a couple examples of how to properly bond CSST.

Note: some second generation versions of CSST, such as CounterStrike, do not have any additional bonding requirements.

How would you know if you had CSST in your home?  Look for flexible tubing with a yellow jacket that covers the ridges.  It’s doesn’t have to be yellow – for instance, CounterStrike has a black jacket, but the majority of CSST in Minnesota has a yellow jacket.  I’ve never seen any other color in person.  This material is not to be confused with an appliance connector, which might have a yellow coating that follows the contours of the ridges.  The photo below shows the two different materials.

CSST vs Gas Connector

The bottom line is that if you have a home with CSST, you should make sure it’s properly bonded to today’s standards, regardless of whether the installation ‘met code’ when it was originally installed.  You can’t grandfather safety.

Additional Information on CSST and bonding

Post Edit 7/9/2013:  The news clip below shows me talking with Kare 11 News about CSST bonding.

Reuben Saltzman, Structure Tech Home Inspections

        


About the Author

Reuben

Reuben is a second generation home inspector with a passion for his work. He grew up remodeling homes and learning about carpentry since he was old enough to hold a hammer. Reuben has worked for Structure Tech since it was purchased by Neil in 1997, and is now co-owner of the company. Reuben’s favorite customers are the ones who have a lot of questions; he grew up thinking he was going to be a school teacher because he enjoyed teaching others so much. In a sense, that’s a lot of what home inspections are about, so Reuben truly does what he loves. Reuben has an A.A. degree in liberal arts and has attended most of the Building Inspection Technology classes at North Hennepin Community College. Reuben and his wife are the proud parents of two young childen, Cy Alexander and Lucy Nicole, and have a German Shepherd named Stanley. With two young children Reuben doesn’t have much free time, but he still tries to play disc golf as often as possible during the summer. Reuben lives in Maple Grove, MN. Professional Qualifications / Memberships: *ASHI Certified Inspector *President, ASHI Heartland Chapter *Member, Minnesota Society of Housing Inspectors (MSHI) *Licensed Minneapolis Truth-in-Sale of Housing Evaluator *Licensed Saint Paul Truth-in-Sale of Housing Evaluator *Licensed Maplewood Truth-in-Sale of Housing Evaluator *Licensed Hopkins Truth-in-Housing Evaluator *Licensed Robbinsdale Point of Sale Evaluator *Affiliate Member, Southern Twin Cities Association of Realtors

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7 Comments

  • Sid 11 MONTHS AGO

    Thanks Reuben. I read that you enjoy answering people's questions (which is much appreciated), so here are a couple more: 1. Is there a special adapter I should use in one of the breakout holes in the top of the electrical panel enclosure to grip the grounding wire after it's inserted into the opening, or will one that grips romex work okay? 2. I'm presuming that the grounding wire should be attached to the grounding bus bar inside the electrical panel where all the other grounding wires are attached, correct? I read somthing somewhere that seemed to suggest attaching the grounding wire to the neutral, but that didn't make sense to me. Thanks again for your help. Sid

    • Reuben Saltzman 11 MONTHS AGO

      @Sid - #1: no, nothing special is needed where the ground wire comes through the panel. #2: yes, and the ground wires and neutral wires will actually all connect to the same bus bars.

  • Sid 11 MONTHS AGO

    Can the copper grounding wire be bare or must it be insulated? Also, can the copper wire be attached to the wooden header in the basement that sits atop the outside concrete block wall as its being strung to the electrical panel? (No risk of fire?)

    • Reuben Saltzman 11 MONTHS AGO

      @Sid - yes, the copper wire can be bare. There is no risk of fire from this wire touching wood.

  • bill 2 YEARS AGO

    These are the type of the posts by you that are really good, they could save lives or even "just" save a house from burning down. Thank you for running your blog.

  • Milind 2 YEARS AGO

    Great post...that was a maddening series of conversations.