nails vs screws

Tonglebeak

I know there are probably a million threads on this, and they seem to say "screws resist withdrawal, nails resist shear. Use nails for framing, and screws for everything else"

What I'm wondering is, is it acceptable to frame with nails, then go back and drill in a screw next to the nails? Wouldn't that give a nice combination of shear+withdrawal resistance?

Willie T

Sounds perfectly logical.

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Willie T

teflonphil

That's what I would do, nail to hold in place so true and plumb, then go around and screw to secure.

Big Bob

now you have done it !

I wonder when this will be required by code.

Daniel Holzman

The best discussion I have read on the subject of nails vs. screws is chapter 7 of Gen. Tech. Rep. FPL–GTR–113. This paper was published by the Forest Products Laboratory in 1999, and Chapter 7 was written by Lawrence A. Soltis. If you can wade through all the formulas and technical discussion, you will find answers to every possible question about the strength of nails, screws, lag bolts, threaded connections, split rings, and a few more exotic fasteners. If this paper is not techical enough for you, I can point you to even more technical reports that explain in excruciating detail the theory of fasteners.

Google Forest Products Laboratory, and you can download this paper in PDF format at no charge. There will be a quiz in the morning.

Big Bob

Daniel,
very good info, but they did not factor in gorilla glue!

Willie T

Gorilla Glue is no good! It's almost impossible to get those big hairy beasts to hold still long enough for it to set up.

__________________
"True eloquence consists in saying all that is necessary, and only that which is."
François Duc de La Rochefoucauld
Willie T

Gary in WA

Some of my tricks I use when framing with nails: angle two nails 1-1/2" apart into the jack/stud combo, every 12" apart with opposing angles every pair, full length of the jack (holds together better while drying out during the building stages) and very helpful when installing doors when shimming against tight stud/jack joints; toe-nail the lower top plate into the header along it's length as well as face nailing through the king stud and lower top plate (angle nail all header end face nails at jacks); start nailing decking ply from the center outward, not to leave a void and poor glue contact; bend a single galv. nail in the middle by hitting with hammer for a 20-30* angle to drive at a toe-nail behind the barge rafters of the gable overhang to positive connect them in the caulking applied while assembling (it will follow the grain into the wood without exiting); toe-nail blocking into TJI's, never face nail to weaken top or bottom chords (against Manufacturer's instructions); drive a 10d nail at a 15* angle at each end of a wall to plumb and line, about 1-1/2" above inside edge, hooking string on one end, make a loop-twist with finger in loop 4-5 times before slipping it on the nail head, then pull it tight with one hand on major string, other on bitter end from loop to get tight, then wrap twice around nail head. Sight wall line from below from stud bay lining wall top plates with string line, nail brace.

Be safe, Gary

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Tonglebeak

That gave me a headache. All in all in is OK to drive a screw next to a nail?

tpolk

dont think screws have been rated yet as a structural fastener for shear as nails have which if tru is a pity

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Daniel Holzman

Certain screws are structurally rated, check out the Simpson web site, they have a series of structurally rated screws designed for use with their Strongtie framing brackets.

Personally I love using screws versus nails, they have fantastic pullout strength, and as long as the shank is appropriately sized, and the steel is the same as the equivalent nail steel, they are just as good in shear. And to answer the OPS, you certainly can drive a screw next to a nail, just keep them separated by at least 3 nail diameters and you are good to go. Also, bore a pilot hole in hard wood, the pilot hole should be the size of the screw root.

One little tip about screws. If you want to draw two boards together, make sure you drill an oversize pilot hole in the first board that is slightly larger than the thread diameter of the screw. Failure to do this will result in the screw locking up, and the boards will not draw together. Alternatively, drive a few nails to draw the boards together, then screw them together. Or, clamp the boards prior to installing the screw.

Tonglebeak

Wow, I did not know Simpson made screws. I remember hearing that they'd only allow nails in their connectors, such as joist hangers. Screws would be awesome

And that "3 nail diameters apart" is the answer I was looking for. Thanks!

tpolk

I bet their screws wont pass inspections without certification from an engineer on a residential build

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The older I get the better I was

oh'mike

Boy I hate to be the one to bring up one silly little point----

To many fasteners in a stud will actually weaken the joint.

I had what one taught to me long ago--More than three nails through the stud(2x4 ) is not good.


That still doesn't answer the screw or nail thing----Why?????--Mike----

Kevin M.

They make screws with thread and shank design to avoid "bridging." Mcfeelys sells them.

Kevin