Proper fasteners for truss hangers

Hey all,

I’m taking the roof inspection course right now, and it mentions roofing nails are improper fasteners for the truss hangers. What are the proper fasteners to use for this application?

This is the page I’m looking at (picture is about half way down on the page):


Joist Hanger Nails.

Welcome to our forum, Adrian!..Enjoy! :smile:

Any of these.


Wow, that was fast! Thanks for the information. I guess there are a lot of different acceptable types. Are we as inspectors generally required to know fastener suitability in many other applications too? Not sure if I would have been able to distinguish the difference in this case. Though I still have a lot to learn, obviously!

You need to recognize the wrong fasteners used on joist hangers that are not allowed like screws, and roofing nails. Some concept of framing nails and their use, of course, is always useful.


Well put Marcel :clap:. I couldn’t have said it better.

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Download a copy of Simpson Strong-Tie’s catalog. They show the different size hangers and the nail size and length requirements. Remember the load carrying capacity of any hanger is based on lab testing using specific nails and nail patterns. Deviate from the size, type or length used in the lab test voids the load carrying capacity shown in the catalog. Here is a link to their current catalog:

Wood Construction Connectors


To answer your original question. It’s a different type of nail.

Look in the table for required nail or screw. Read all the other information Simpson has to offer on the correct and incorrect application of their hangers.

Then identify nails because if the nail is in the wood how else are you gonna know the size or type?

Off topic Sidenote - some sinkers have larger heads than common nails. So doesn’t mean it’s a larger diameter nail.

  • Framers have been putting incorrect nails in for years since the implementation of the pneumatic nailer

This is the page that would help the most here;


Welcome to the forum, Adrian. Enjoy.

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If you don’t use the correct fasteners. You will split the truss at the top plate. And that right there will lose structural integrity at that point.
On all of the homes we have been building lately. The engineering will give you the proper fasteners and clips or straps.

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All hangers require minimum #10 hanger nails, not #8 (number stamped on the head) but you’ll see a lot of #8 and even 8d sinkers which are definitely inadequate.
There are hanger types you’ll see over and over (LU and LUS series). Pretty easy to memorize the fastener requirements once you have the Simpson Strong Tie Catalogue. Their catalogues are free so you can order hard copies also.
The catalogue will list all the different wood-connecting hardware and the acceptable fasteners, since many have more than one acceptable type.

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I checked out the catalogue, and it looks like different fasteners can be used depending on the engineered load for different hangers. Are inspectors required to know if the hanger is appropriate for the load it is carrying? Or should we mostly me looking for signs of failure to point to it being undersized?

Also, it looks like it could be possible to use the right type of nail, but wrong length, as well. Are there signs of improper length fasteners that I should be looking for?

You don’t have to confirm that the proper connector was used, but you want to be able to identify when a connector was used in a manner for which it was obviously not designed, or fastened with fasteners that are obviously incorrect for that application. 8d sinkers are always wrong. #8 nails are usually wrong, but both are common in some areas (S. CA for sure).

Different connectors are made from different gauge steel and designed for use with different types and numbers of fasteners. Few, if any of us, have all that memorized.

Typically, you’ll just be judging from the head of the fastener whether the correct one was used. The vast majority use #10 hanger nails until you start seeing heavier gauge connectors, usually hangers and straps, and then you’ll be looking for the heads of the larger fasteners you saw in Marcel’s chart.

There’s a lot of good information in those Simpson catalogues. If you have time to actually read through the general information and the fastening requirements for common connectors you can learn a lot in an hour!

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Thanks for the clarification! There’s a lot of good info in the Simpson literature - it could almost be a whole course in itself.

I’ll make sure to study up the fastener types, sounds like it can be useful in a lot of other scenarios, too.

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