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most guys tell me you need to use 5/5" plywood for roof sheathing,1/2' is a tad to thin to properly hold nails. this true?
they also say plywood needs to be spaced a tad. is this necessary even if the sheathing is dry? i thought it only needed to be spaced if it was damp or wet.
 

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copper magnet
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most guys tell me you need to use 5/5" plywood for roof sheathing,1/2' is a tad to thin to properly hold nails. this true?
they also say plywood needs to be spaced a tad. is this necessary even if the sheathing is dry? i thought it only needed to be spaced if it was damp or wet.
I assume you mean 5/8".

I see 1/2" used all the time. I prefer 5/8", especially on 24" centers.

Yes, it should be spaced both directions.
 

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Almost everything here is 3/8" :jester: oh wait, that's osb.

5/16" can do on 16" centres, provided the roof material is relatively light, although personally I wouldn't. 1/2" is ok for heavier items with 16" on centres. 5/8" is really solid stuff, and minimal really for 24" centres. It is fairly common to run into 3/8" on reroofs and occasionally 1/4" :blink: . Having said all that, your location may vary with regards to codes, and I recommend going the extra if at all possible, this is your roof, it keeps the outside world from making your inside world suck.

Thicker wood means better holding power for the nails sure. I don't actually recommend roofing hand nails btw. The lack of barbs or spiral means they generally dont hold as long as the shingles should last.

Minimal spacing is a good thing. Tight butts are not. :confused:
 

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New houses here have 24" OC rafters, 1/2" OSB with H clips. Holds just fine. 5/8 though is obviously better. Not a fan of plywood though.
 

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^^^ what he said.

around here, most of the houses built in the '70s were decked with 3/8" and now it de-laminates as soon as ya tear off. the glue holding the plys together has long since "failed", and the only thing holding it together are the roofing nails. rip the shingles (thus pulling all the nails), and the plywood is shot.
 

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Same thing as MJW.

I did a house once that has 1/2inch plywood every 12OC. You could drop a truck on that house and it wouldnt move. Guess the original owner built it himself and went a little overboard.
 

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Same thing as MJW except the OSB thing, I am not a fan of osb and seldom see it used for roofing except in production sub divisions. One spec and custom homes it's almost always CDX. I prefer CDX, but we've all had this discussion before. Also the clips are hit or miss you sometimes see them, but not always.

On 50 year old homes, it's not uncommon to see 3/8. Those homes nearly always require a complete redeck. In that case we use 1/2" CDX.

If it were my house no less than 5/8" CDX and maybe even 3/4".
 
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