Joists hangers

Page 1 of 2  
Can I use screws instead of nails to attach joist hangers to joists?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Sasha wrote:

Yes, of the proper length, etc. http://www.strongtie.com/products/connectors/HUCQ.html
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I'm no engineer, but some manufacturers recommend a certain type of nail/screw. I think it's a shear strength issue...
Tim

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
DiezMon wrote:

Yes...there will be allowed sizes(lengths)/material/strength reqm'ts listed...
Don't use a drywall screw, iow, even if it long enough.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Sasha wrote:

Why would you want to?
R
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

stronger than nails. when you break off a few just tightening them by hand, you realize that they are made from low stength material that is unsuitable for any important holding task.
my experience is with roberson wood screws available in canada at hd and cdn tire. there may be better but i can't find them. ....thehick
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
frank-in-toronto wrote:

I like to use spiral nails. Tony
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Tony Hwang wrote:

I've never seen 1.5" hot-dipped galvanized spiral nails. In any event, it's unnecessary. Spiral nails, like screws are meant to keep the fastener from backing out. If you use the 1.5" joist hanger nails, they're not backing out. There's not enough embedded length, and if you've ever tried to pull one of them you know the galvanzing might as well be glue.
R
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

there.
Sometimes the vibration from hammering can knock other stuff loose (like plaster) particularly in remodelling.
Screws allow for (easy) disassembly if you goof or just change your mind. (the main reason I use them inside)
More holding power particularly in soft woods
Use steel screws labeled for general carpentry use. I use 3" #8 screws for most interior joining (I am a homeowner not a contractor). Drywall screws are made of a weaker alloy and with less metal since they only need to hold up a modist load.
Screws are a little slower to use than nails though and cost a bit more
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
It is the diameter of the fastener that is most important factor for installing hangers. That is why they require the special 10d x 1.5" nails. An 8d common nail is not the same and does not meet the design criteria for sheer strength. Simpson is very clear on this. If you use screws then the core of the screw (the center part, without grooves) would need to be the same diameter as a 10d nail, which means approximately a 3/16" lag bolt. You'd then have to drill out every hole in the hangers, because they are not big enough. A joist hanger can reach it's design loading only when every nail hole is filled. That is why cheap hangers have so many holes. You might be able to get an engineer to certify that the screws you are using have an equal sheer strength as a 10d nail. Regular joist hangers are designed to support vertical loads. They are not specifically designed to handle horizontal forces of any magnitude. There are special hangers and connectors made by Simpson and others to do that.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Good post, BP. Very informative.
BP wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
BP wrote:

Which would totally change the load capacity of the hanger and expose bare steel. Extremely bad idea, and I'm sure you're not recommending it.

Why does the hanger quality or price (not sure which cheap you mean) have anything to do with the number of holes? A certain number of fasteners are required to develop the rated load capacity - that's the only determining factor on the number of holes in a hanger.
R
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

No, not recomending it. Anyone crazy enough to drill out every hole in every joist hanger probably can't read.

The quality of the hanger, and it's price, is determined by the type and gauge of steel they use to manufacture them. Cheaper, weaker steel would fail sooner with 6 nails in the hanger than a hanger that was made with stronger, thicker steel. The manufacturers compensate for this by increasing the number of nails in order to receive the same design rating as the competition. Unfortunately, most framers do not/will not fill every hole in a hanger with 12 holes so the hangers will not deliver full design loading. Fortunately, these things are way over-designed, so we don't see any buildings falling down. But they over-design because they compensate for real world factors like framers not putting all the nails in.
I had an inspector fail a frame once because of the joist hanger nails, citing the info above. That when I checked it out and found him to be correct.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
BP ( snipped-for-privacy@only.net) said...

So too would be a good building inspector! When we built our home, our inspector checked that the proper nails were used for the joist hangers.
Mind you, the special nails on Simpson hangers are for holding the hanger on the ledger board. The two (or four, depending on size) angled nails that hold the joist onto the hanger may be regular common or spiral nails.
--
Calvin Henry-Cotnam
"Never ascribe to malice what can equally be explained by incompetence."
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
BP wrote:

Only the shaft of the screw is bearing the shear load...if it is of equivalent diameter and and strength, the shear strength at the hanger will be as high as the nail. It wouldn't be out of the question to use a SS screw that would have higher shear strength at the same diameter...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The screw / nail bears some of the shear force - the clamping force of hanger against joist (both faces) also bears some, and probably this clamping force is higher if using modern twin helix screws tightened correctly.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Phil wrote:

Yes, there's much more than I mentioned, just pointing out it wouldn't take anything close to a 3/16" lag to get equivalent shear strength to a 10d common nail...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The hole in a hanger is just big enough to fit a 10d nail. The screw would have to be twice that size (assuming the threads account for half the diameter). Stainless screws or screws that are made of (more) hardened steel could be smaller. But you still need to find the design data to prove this.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
BP wrote:

The diameter of the shank is all that is actually resisting the load in shear--not the threaded portion. it's inside the beam or joist...I never did nor am I claiming it has been approved, only that it isn't anyways near a 3/16" lag to get an equivalent area for the shear load...

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Duane Bozarth wrote:

Are either of you Jesuits? "How many angels can fit on the head of a pin?"
I still don't know why you'd want to use screws in the first place. I've never found a situation that I couldn't nail and nails are cheaper, faster and there's no arguments about angels and pins. ;)
R
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.