|
East of Broken Bow | I have a relative who is a carpenter who actually went to school to learn where to use screws and nails and which kind to use.
First of, proper construction screws are every bit as strong as nails, even for shear strength. The problems we see are very, very few use the proper construction screw rated to the same shear strength as nails because they are mega pricey compared to even ring shank or pole barn nails, which hold just as good in structural uses. He only uses these in areas where it is difficult to swing a hammer, or where swinging a hammer could cause damage to something (like crack a window or such). However, you have to check the shear strength of the screw. If you just use the pullout rating, it will not be as strong because a screw with the same pullout as a nail will be notably thinner.
The other place for xcrews in construction is where you want things drawn to a certain tension, and kept there. Nails, even ring shank nails bend the wood fibers down as they are driven, and over time the wood fibers can straighten making the nail slightly loose. This is why a floorboard creaks after a while, even if it was nailed down tight. Screws cut the wood fibers, and actually bend them slightly 'up' so as they try to straighten, they hold the screw tight. Screws are better than nails for things like floorboards and roofing steel, to name a couple.
Otherwise, the most cost effective way to securely join wood together would be cement coated sinkers. In a nail gun they don't really draw the boards together, but they hold really well, install fast, and are cheap
Hand hammering nails draws the boards tight, and you are supposed to hammer the head flush or even in a slight dimple. This bends the wood fibers under the head more than enough to compensate for any loosening of the shank from the bent wood fibers from driving the nail.
Lastly, if you have a lot of pole barn nails to drive, he had a funky little air hammer that you held in your hand, and even had a strap to hold it in place kind of like a corn husking hook but with an air hammer mechanism where the hook would be. You put a nail into a little sleeve built into it, and when you pressed the point of the nail against the board pressure from the nail head in the sleeve would start it hammering the nail into place. As long as you 'pushed' against the nail, it would keep hammering. That thing could drive in any nail that you could get to fit into the sleeve, and would drive it flush with the board. I got one similar to that, and use it with smaller punches for driving out things like roll pins in hard to reach areas, just turn down the air pressure and it's as gentle as you want it to be. | |
|
Screws vs Nails
