# framing screws



## vos (Apr 6, 2010)

what screws if any can you use for framing?


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## carp.780 (Jan 2, 2010)

Why bother? Screws have very little shear strength compared to nails and take much longer to put in.


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## HandyHails (Feb 28, 2009)

But Mike Holmes said................


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## Mark Siders (Dec 11, 2010)

Use both screws and nails and you cover all your bases. :thumbup:

Hope speed isn't a factor :blink:


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## TNTRenovate (Aug 19, 2010)

Perfect example is when you demo.

I have never seen anyone pull out a drill to remove a drywall screw after pulling down drywall. What do you do? You take you hammer and smack it at an angle and snap goes the head clean to the lumber. Try that on a 16d framing nail...:whistling


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## Remodelor (Nov 5, 2010)

Most codes call for nails, however I believe Simpson makes approved screws for their fasteners. That said, I don't know if they make a code approved wood-wood screw.

The shear strength argument is a valid point, however it's often tested very poorly. People often confuse metal fatigue with shear strength. The nail > screw argument is usually justified by someone driving a nail and a screw halfway into a board and then bending them over. The screw, which has high-carbon steel in it and is therefore more rigid and brittle, succumbs to metal fatigue, and snaps. The nail, made of a softer steel, bends back and forth. So most people assume that screws will just snap when an excessive load is applied.

I witnessed another contractor show me his test to justify his use of construction screws. He took a 2x4 and nailed a block in it with a single 16 penny nail completely sunk. He then proceeded to strike downward on the block with his hammer. The nail slid out after 3-5 moderate strikes of his hammer. He then did this with a 3" construction screw. The screw didn't budge or shear because it was not free in space to be bent to such an extreme. Anyone who's ever tried to demo screwed framing can attest that they don't easily shear when they are sucked down tightly in a board. On every single occasion of demolishing screwed framing, I've found the wood will splinter and break apart, leaving the screw bent but intact.

Now neither of these tests are empirical studies, however I'd love to try some practical stress tests of framing and fasteners sometime to evaluate if nails truly are better than screws.

Personally, I think screws > nails. Here is a link to some of the best structural screws on the market, link. Below is an image of the test. Try it at home!


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## Inner10 (Mar 12, 2009)

> The shear strength argument is a valid point, however it's often tested very poorly. People often confuse metal fatigue with shear strength. The nail > screw argument is usually justified by someone driving a nail and a screw halfway into a board and then bending them over. The screw, which has high-carbon steel in it and is therefore more rigid and brittle, succombs to metal fatigue, and snaps. The nail, made of a softer steel, bends back and forth. So most people assume that screws will just snap when an excessive load is applied.


You sir are correct, although I spoke to an engineer and he said that the shear strength is lower where the threads are twisted on the screw, and in the case of a bolt it will shear along the cut of the thread. On that explanation I assumed that is why they use smooth shoulders on bolts where shear strength is important.

As for the question of "CAN" I would check with your AHJ, around here I'm sure you can use any.

But on that note screws cost more and take more time.


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## Remodelor (Nov 5, 2010)

True enough. Framing is much easier with nails. I just wanted to head off the argument that screws are going to snap like twigs when weight is applied, which is certainly not the case. There are times when screws are easier and more controllable. Furthermore, there are times when you want something to *really* hold, like the blocking you mount a ceiling fan box to. Also, remodelers often don't use nails because when we frame, there's often drywall on the other side of the wall or below us. If we start using a nail gun or a hammer, we get pops on the rock. Screws are nice and gentle.

By the way, if you look at the shear rating for those GRK screws on the link I posted, a standard 3" framing screw has something like 2000 lbs before it snaps. I'm curious what the shear rating (at the smallest thread) is on a 16d common nail. One company had something like 160 lbs, but that seemed awfully low, as if the two tests were different. Anyone out there know the shear strength of a 16d common?


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## Dirtywhiteboy (Oct 15, 2010)

Remodelor said:


> Most codes call for nails, however I believe Simpson makes approved screws for their fasteners. That said, I don't know if they make a code approved wood-wood screw.
> 
> The shear strength argument is a valid point, however it's often tested very poorly. People often confuse metal fatigue with shear strength. The nail > screw argument is usually justified by someone driving a nail and a screw halfway into a board and then bending them over. The screw, which has high-carbon steel in it and is therefore more rigid and brittle, succumbs to metal fatigue, and snaps. The nail, made of a softer steel, bends back and forth. So most people assume that screws will just snap when an excessive load is applied.
> 
> ...


I don't like your test:no:In my block I'll shoot 3 HDG 16d at an angle downward faster than you'll sink your screw, now insted of pounding with a hammer because that's not how load force works let's just hang weight from it and see what happens???:clap:Can the testing board at CT please conduct this test for us?:w00t:


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## TNTRenovate (Aug 19, 2010)

Dirtywhiteboy said:


> I don't like your test:no:In my block I'll shoot 3 HDG 16d at an angle downward faster than you'll sink your screw, now insted of pounding with a hammer because that's not how load force works let's just hang weight from it and see what happens???:clap:Can the testing board at CT please conduct this test for us?:w00t:


I guess I am confused. Isn't most framing shot vertically and not horizontally? So why is shear load a factor?


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## WarnerConstInc. (Jan 30, 2008)

GRK's if you got use screws.


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## aptpupil (Jun 12, 2010)

grk's are awesome and i think that's what mike holmes uses so go crazy. we'll see you next year when you're ready for the roofers.


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## WarnerConstInc. (Jan 30, 2008)

aptpupil said:


> grk's are awesome and i think that's what mike holmes uses so go crazy. we'll see you next year when you're ready for the roofers.


He uses #2 Robertson's just like all the other brainwashed Canuck's.:laughing:


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