Reuben's Home Inspection Blog


Joist Hanger Installation Defects

Just a little over a year ago, I took a class put on by one of the largest manufacturers of metal brackets, Simpson Strong-Tie.   That class was a real eye opener – I realized afterwards that just about every deck that I inspect is constructed wrong.  Not all of the installation defects are major, but they’re always worth pointing out.  Today I’ll talk about one of the most common installation defects that I find with joist hangers in the Twin Cities – improper nails.

You thought I was going to say missing nails, didn’t you?  Too easy, too obvious.

Wrong Nails If the wrong nails are used at a joist hanger, it won’t perform as intended. To know what nails are supposed to be used, you first need to know what joist hanger you’re working with.  The most common joist hanger I find on decks is a LUS28*.  This joist hanger can be used with 2×8 and 2×10 joists.  Now that I know which hanger I’m using, I can go to the Simpson Strong-Tie web site to find out what fasteners are specified.  To see the full page I’m looking at, click here.

LUS28 Fastening Requirements +

As you can see, this hanger requires 6-10d nails + 4-10d nails.  The big defect that I often find is that 10d x 1 1/2″ nails are used in place of 10d nails.  If you look down on the far right column of the above chart, you’ll notice only a few hangers will allow a 10d x 1 1/2 nail.  So what’s the difference between the two? Quite a bit!  The photo below shows the two next to each other.

Joist Hanger Nail Comparison

Now here’s what the nails would look like if driven in to the floor joist.  You can see that the smaller nail isn’t long enough to even begin to penetrate the ledgerboard.  Click the photo for a blowup.

Nails in joist hanger

The really crazy thing about this is that the nails that are so much smaller are actually called “Joist Hanger Nails”!  They’re called joist hanger nails because that’s about the only thing they’re good for… but they’re usually not even good for that.   If you go to Home Depot and you look at their joist hanger display, you’ll probably find boxes of joist hanger nails sitting with the rest of the joist hangers, and no other types of nails. I’m pretty sure that’s why these nails get used improperly so often.

To identify these “Joist Hanger Nails”, all I need to do is look at the head of the nail.  They all have a big “10″ stamped on them.  Standard 10d nails don’t have this.

Joist Hanger Nail Head Blowup

How serious of a problem is this? The manufacturer will allow these nails in to the header, but the total load will need to be reduced to 64% – a huge reduction.  The manufacturer does not allow these nails in to the joist.  I sent the manufacturer two separate emails to find out what the reduction factor would be if they were used in the joist, but after ten days, no reply.

I meant to make today’s blog about all of the different defects that I find with joist hangers, but this one defect just ended up being enough for a full blog.  More on joist hanger defects later.

Joist hangers meant to be used outdoors or in contact with treated lumber will often have “Z” at the end of the model number.  In my example, the joist hanger used for a deck would actually have a model number of LUS28Z.

Reuben Saltzman, Structure Tech Home Inspections


Comment balloon 15 commentsReuben Saltzman • February 02 2010 05:03AM


Well written and of great importance!  Those hangers carry a lot of weight and in time they will "stress out" if not installed properly.  I have done a lot of carpentry in my 71 years and only today learned that a 10-d could come in 2 lengths.  I suspect that to do so is a stretching of the English system used to identify nails.  What do you think?

Cheers from Jim-in-Paradise

Posted by James Bath, REALTOR® , AHWD® , SRES® ,e-PRO® (Gulf Shores Realty) over 9 years ago

Good information to know. Thanks for taking the time to post.

Posted by David Jirasek, ALC, CCIM (Jirasek Realty) over 9 years ago

Good information. Thanks for sharing. Another good reason to have an alert home inspector.

Posted by Roy Kelley (Realty Group Referrals) over 9 years ago

Hi James - it would be nice if these nails were called something else.  There would probably be a lot less confusion.

David and Roy - thanks for reading.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 9 years ago

Great info on the proper installation of joist hangers.

Posted by Ken Greene (Hudson-Mohawk Inspections, LLC) over 9 years ago

Reuben, very interesting story about the short "joist hanger" nails.  To make the issue worse, and part of why they still get used, is that whenever you bought hangers----I am going back to the 70's now----those short nails came in bags inside the box of bulk hangers you bought----all sorts of sizes and types of hangers.  Most of us just left them in the box:)  At any rate, this may be why they have such a long legacy of being used as "joist hangers"

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) over 9 years ago

Reuben,  Wow just add that to the list of things that are wrong with decks!  You are definitely right about more of them being wrong than right.  This is great information to watch for,  I thought I was doing good spotting a 2x6 hanger on a 2x8.......

Posted by Jim Allhiser, Salem, Oregon Home Inspector (Perfection Inspection, Inc.) over 9 years ago

Charles - they actually used to include joist hanger nails with the hangers?  What a concept.

Jim - If you have a chance to attend a seminar put on by Simpson Strong-Tie, do it.  Great information.

btw - the LUS26 joist hanger (a 2x6 hanger) can actually be properly used on a 2x8.  Just when you thought you had it figured out, right?

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 9 years ago

Side note for home inspectors:  I keep a pry bar in my truck, so if I see nails with the "10" on the end, I'll pull one out, set it on my tape measure, and take a picture of it.  These short nails come out VERY easily, and they will usually go right back in with a push of your thumb.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 9 years ago

Awsome post, always very informative

Posted by Der Hous Inspector LLC, Certified Master Inspector CMI (Der Hous Inspector) over 9 years ago

Great post Reuben. Very informative. I will check out that website a little more in depth. That is something that all  home inspectors can and should use. Thanks.

Posted by Ian Niquette (Square One Home Inspection) over 9 years ago

Eragorn - thanks for reading!

Ian - I agree.  If nothing else, watch out for that "10" on joist hanger nails, especially if the nails are supposed to be driven in at a 45 degree angle.  Always a red flag.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 9 years ago

We have a great Simpson rep out here who gives seminars to HIs all the time. I have attended the deck one at least three times. Last time we had him discuss structural issues to do with hangers etc. Much of what you said here I have heard from the rep out here. Simpson is a great resource for information.

Posted by James Quarello, Connecticut Home Inspector (JRV Home Inspection Services, LLC) over 9 years ago

James - that's exactly where I got this info.  I might have a few more blogs coming on similar topics...

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 9 years ago

Just stopped by to let you, and anyone reading this, know that there's an ActiveRain Super Bowl Party going on. Stop by if you have a chance.

Posted by Not a real person over 9 years ago