I recommend you re-read the comments and answers I’ve given here. The solutions to your problems have already been given.

The problem with 10d 1-1/2″ nails isn’t their shear strength – you’re correct, that doesn’t change. The problem is their holding strength. I received this email on March 25th, 2010 from a Simpson Strong-Tie rep:

Hi Reuben

I am the local Territory Manager in MN and was forwarded your blog regarding improper nail installation. I am sorry you have not gotten a response until now, feel free to contact me or Nick Varien (nvarien@strongtie.com), I am guessing you may have sat through Nick’s session in November of 2008.

Here are a few details regarding your LUS28 discussion. I verified with our engineering department today that if a customer called with this problem, we would not load rate this application, per footnote 4 on page 16 of our C-2009 catalog. While we know the nails installed carry some load, we don’t know how the hanger will actually perform when loaded to capacity- EG, the failure mode may be nail pull out before the nails reach their calculated shear value, thus lowering the capacity even further. For the sake of discussion, you could calculate the reduction as shown below, but as I noted above, we would have concerns about some of the nails being withdrawn from the material before the calculated loads are reached.

LUS28 SYP floor load =1055
6 10d common face nails- 1055 x .6 x .77 = 487 lbs. (the .77 nail reduction is found on page 16)
4 10d common joist nails- 1055 x .4 x 0 = O Lbs load (these nails do not penetrate the header)

So from purely a calculation standpoint the load is slightly less than half.

Also, I believe Home Depot does stock the 10D common and the 16D common Hot dipped galvanized nails from Simpson Strong-tie. They are normally merchandised in the Simpson Joist hanger section. Our 10D x 1 ½ nails are not labeled as joist hangers nails, rather N10D and there is a partial listing found on the nail packaging of which hangers these nails fit. This packaging was modified about 8 or so years ago to clarify the applications. Some of the “generic” manufacturers of these types of nails still use the Joist hanger label for 1.5” nails though.

Please don’t hesitate to contact me if you have further questions- your blog did have some excellent and insightful information.

Thanks
Curt Johnson
Senior Territory Manager
Simpson Strong-Tie

If a nail is stamped 10D, it will be a 1-1/2″ nail. Full size 10D nails don’t have that stamp on their heads.

Also, I stopped by Home Depot and took a photo of the nails that they had sitting next to the joist hangers; while Curt was correct, they’re not labeled joist hanger nails by Simpson, they ARE labeled as joist hanger nails by Home Depot. You can see a photo below.

Thanks for reading.

Like David said above, the 10d nail from a joist hanger nailer can be used at the perpendicular attachment of the joist hanger to the header provided they are stamped 10d. A 10d nail is a 10d nail no matter the length. However, the reason they specify full length nails is only for the diagonal installation. Other wise, like David said, the perpendicular nails will stick out of the header material and not provide any extra shear strength. Because the nail is longer it does not affect the shear load it will break at, it depends only on the diameter.

You could still use 10d 1-1/2″ nails to attach the hanger to the header, but you would need to calculate the appropriate load reduction. Standard 10d nails should still be used in the joist.

There was no mention of the screws at the time I took the class, but they look like a great product. http://www.strongtie.com/products/connectors/screws-loadrated.asp

Was the use of Strong-Tie screws talked about in your class? If so, any comments on using Strong-Tie screws versus 10d joist nails.

“Yes, 10d nails need to be used on the diagonal, but the “joist hanger nails” are used to attach the joist hanger to the header.”

That’s not correct – the manufacturer specifies full 10d nails in to the header. Just check the chart that I included. As I mentioned towards the end of my blog, the manufacturer will allow 10d 1-1/2″ nails at the header, but the load capacity gets reduced to 64%.