How many screws per board?

[ultrarunner]

Lowes and Menards and other stores sell 4x10' plywood but it usually has to be special ordered.

We did a garage with 9' T-11 siding... all vertical... it is the same one where I had to follow the 4" perimeter and 12" in the field nailing schedule.

 

[LD1]

Lowes and Menards and other stores sell 4x10' plywood but it usually has to be special ordered.

IF it makes sense to use 4x10 sheets (less waste, quicker, or whatever reason), go for it. But I always try to plan around using 4x8 sheets, cause the 10' sheets cost more per square foot, and are usually special order.

Lumber is the same way. It is usually the cheapest per foot in 8' lengths. 6', 10', and 12, are all usually more per foot.

 

[CurlyDave]

Here is a drawing of how the plywood is to be placed. Like others have said running the boards horizontally allows each board to be screwed in to more boards reducing the change of racking. I am aware of the nail vs screw debate and in this application the boards won't be holding a load so I am not worried about them shearing. View attachment 355581

As has been stated those are shear walls, and while they do not carry a vertical load, they are loaded in seismic events and during winds.

The wall with the doors is the most critical in that plan and may require a different nailing schedule than the others. If the building is being inspected, you are going to need approved plans. The architect or engineer who stamps the plans should provide a nailing schedule for each wall. The inspector will inspect to the plans.

While ring shank nails are fairly common, they have recently been found to damage the panel they are driven through, and are sometimes not allowed. Two years ago in CA, I was required to use "screw nails", which are the ones which have twisted flutes along their length. Galvanized vs. non-galvanized, cement coated (not portland, but heat activated glue) vs. plain and smooth vs. ring-shank vs. screw nails are all possibilities.

Bottom line: don't buy the nails until you have the stamped plans in hand, and then get the ones specified.

As others have stated screws are generally not allowed as they are usually brittle and do not have shear strength required for this application.

Use a good nail gun to place these nails. The ones I have seen on most job sites are Hitachi. If you are buying a new one, be sure it will take full 16d common nails. There are a lot of nail guns out there which will not take full round head 3-1/2" long 16 d nails. Some only take clipped heads, and some only take goofy-looking nails with the head not centered on the shank. Some will claim to take 16 d nails, but the ones they use are only 3-1/4" long.

If you get a Simpson Strong-Tie catalog in the back there are shear values for many nail sizes and designs.

 

[EddieWalker]

Horizontal compared to vertical for strength is really just splitting hairs. Both have their pros and cons, but in the grand scheme of things, it really doesn't matter. For racking, having a sheet standing up at the corners is better if it covers both the sill plate and top plates. If you can't cover both, then it wont make any difference.

Siding does two things, it stops racking and it holds the top and sill plates together. Zip System has 9 foot sheets that are great for this and by far the best thing out there. They also have longer sizes, but I'm not sure of all the options there. I've used 9 foot lengths and really like them.

Ring shank nails give you the best of both worlds when comparing nails to screws.

I prefer OSB over plywood. For sheer strength, they are both the same, but for attaching stuff to them, like siding or shingles, OSB doesn't come apart like plywood does. I would never use plywood on a house for siding. For flooring, I'm fine with either plywood or OBS as long as they are tongue and groove. For floors I would only use screws or ring shank nails along with glue.

I've never used 3/4 plywood for siding or decking a roof, so that might be fine over OSB if you want to spend the extra money and go through the extra work of handling the heavier material. Do you have a reason for going with 3/4 plywood?

Ultrarunner nailed it on how many nails or screws to use.

Eddie

 

[Egon]

Screws come in many and varied design. It's a mater of picking the right screw.

There is information on the internet.:thumbsup:

 

[ultrarunner]

Screws come in many and varied design. It's a mater of picking the right screw.

There is information on the internet.:thumbsup:

I didn't have a choice as my project had to be inspected and finaled by the Building Dept.

 

[JDgreen227]

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.

 

[turnkey4099]

Here is a drawing of how the plywood is to be placed. Like others have said running the boards horizontally allows each board to be screwed in to more boards reducing the change of racking. I am aware of the nail vs screw debate and in this application the boards won't be holding a load so I am not worried about them shearing. View attachment 355581

My preference is nails. Cheaper and much faster/easier to install.

Harry K

 

[kevinwak]

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.

Sent from my iPhone using TractorByNet

 

[UpToNoGood]

I did call Lowes and they have the plywood in 10' length, but can't get a price until Monday. However the guy at Lowes did say it would be regular price for a 10' and no special order fee. I am willing to pay more as long as it is not outrageous for the 10' so it will save me time installing and not cutting.

As for OSB over regular plywood I will always pick plywood even if it does cost a few dollars more. 1/2 would work for what I am doing, no reason for the 3/4. I will wrap the plywood with tar paper and then metal sheeting.

The building is not being inspected, but I do want to keep things up to code.