How many screws per board?

[JDgreen227]

Take a 2" screw and screw it 3/4 of the way into a board. Next give it a hit with a hammer. It will usually shear clean off. This is the demo I have used to explain to people why they aren't allowed in shear applications.

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Yes, screws will shear when you do that, but in real life applications like using screws to attach boards, sheathing, and siding, how can the screw head be sheared off when the entire board or siding section is butted up against another one? Even with spacing clips, when properly installed with the recommended fastener spacing you are gong to have one (bleep) of a time getting enough lateral movement to shear a screw off.

 

[ultrarunner]

I've always used plywood untill reading Eddie's posts.

The last job was a wood shingle tear-off over skip 1 x 4 sheathing.

I used OSB and I'm ok with it... inspector said it has better water resistance due to the binders.

Then again, the biggest gap it was bridgeing was the 4"

 

[Egon]

There are screws that will work for wood construction. Perhaps they have to be specified on the plans? They probably have to be ordered as the local hardware will not have them.

For sheathing I'd prefer solid one inch boards. Next would be plywood. OSB would remain at the store. The new houses are much more flammable than old house's.

 

[tallyho8]

If I were a betting man, I would bet that 3/4 plywood would be much stronger than 1x8s if installed properly. However, after Katrina you would have been amazed at all the plywood sheathing that blew off because it was only held on by a few nails because the installer used a nail gun and couldn't tell when he missed the stud. I saw some panels that had less than 1/3 of the nails hit the studs. If you were using a hammer, you would know instantly if you missed the stud.

In this area our 1/2 OSB is much better than our 1/2 plywood sheathing which is usually warped and coming apart. And it cuts much easier than the plywood and seems to hold nails better. I would never use the 7/16 OSB than is getting so common now. And thank goodness they stopped using particle board.

 

[JDgreen227]

An inexperienced user wielding nail guns for framing and sheathing usually does pure crap work. It never fails to amaze me how many new homes I see that are merely tacked together because the operator doesn't know or care if the nail hits anything solid or drives the wood together. Swing a hammer while framing or sheathing and the blow will drive the wood together and as Tallyho8 says, when you are pounding a nail you KNOW when the pointy end hits air. As a former jack of all trades carpenter with over 34 years of experience, I say NOTHING beats 3/4" CDX plywood for construction strength.

 

[UpToNoGood]

I plan to do all my nailing with a hammer.

 

[EddieWalker]

I must disagree when it comes to choosing OSB over REAL plywood. Take a one foot square of 1/2" OSB and the same size square of 1/2" CDX plywood, support them on lengths of 2X4 with about 6" of unsupported length in the center and bang in the center with a hammer. The hammer head will punch thru or break the OSB, but bounce off the plywood. I'm sorry they ever invented that cheap s**t OSB crap. It's nothing but sawdust and glue, it's ugly and dulls cutting blades quicker than real plywood does.

About nailing spacing, I always tried to space nails for sheathing about 10" apart, using a standard hammer handle length to measure for works great for spacing.

I wont disagree with your test, but don't really understand what hitting it with a hammer has to do with the ability to hold nails, which is what OSB is a lot better at doing then plywood of the same size. I'm not anti plywood, in fact I use it all the time for cabinets, shelves and sub flooring. What I don't like is how it splinters and falls apart when nailing shingles on to it or siding. The reason OSB is better is that the nails go through it cleanly and hold them much better. When going through an attic and looking at the difference between plywood and OSB, there is a huge difference in how badly the plywood comes apart compared to OSB.

I think sheer strength is the same between either of them, or it's to insignificant a difference to matter.

Eddie

 

[PILOON]

In my area we have metallic wind braces. They are like a T shaped (much like a T bar) but of heavy galvanized tin.
You snap a chalk line like 30-45 deg from corner top down catching as many studs as possible and then a shallow saw cut to the depth of the T.
2 nails at every stud and then just try to rack that end wall.
Much stronger corner than any plywood or OSB can make.

 

[PILOON]

In my area we have metallic wind braces. They are like a T shaped (much like a T bar) but of heavy galvanized tin.
You snap a chalk line like 30-45 deg from corner top down catching as many studs as possible and then a shallow saw cut to the depth of the T.
2 nails at every stud and then just try to rack that end wall.
Much stronger corner than any plywood or OSB can make.

 

[ultrarunner]

A very good friend builds expensive custom homes... he insists his guys drive nails by hand for just about everything... he does have palm nailers for areas where hammers can't be swung...

No slap together get it out the door for his crew... homes generally in the 1 to 2m range on steep downslope lots with magnificent views for the Bay Area.

If I were a betting man, I would bet that 3/4 plywood would be much stronger than 1x8s if installed properly. However, after Katrina you would have been amazed at all the plywood sheathing that blew off because it was only held on by a few nails because the installer used a nail gun and couldn't tell when he missed the stud. I saw some panels that had less than 1/3 of the nails hit the studs. If you were using a hammer, you would know instantly if you missed the stud.

In this area our 1/2 OSB is much better than our 1/2 plywood sheathing which is usually warped and coming apart. And it cuts much easier than the plywood and seems to hold nails better. I would never use the 7/16 OSB than is getting so common now. And thank goodness they stopped using particle board.