Home>Discussions>EXTERIORS>Which Roof Sheathing? 5/8 OSB vs. Plywood
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RISurfer
Which Roof Sheathing? 5/8 OSB vs. Plywood

I am planning an addition. I will be using 24' trusses 2' OC. The truss manufacturer recommend for exterior roof sheathing 5/8 tongue and groove Weyerhaeuser OSB. I had originally planned to use 1/2 plywood with clips. Any recommendations? Pros vs. cons between the 5/8 osb vs the 1/2 plywood?

A. Spruce
Re: Which Roof Sheathing? 5/8 OSB vs. Plywood

Plywood would be my choice as well. If you use 5-ply then you can get away with 1/2" because the more plies the stronger the plywood. The cheaper and more typical 3-ply won't be strong enough to span the trusses.

Timothy Miller
Re: Which Roof Sheathing? 5/8 OSB vs. Plywood

Howdy, plywood does not DE laminate when wet . OSB does turns to mush - remember it is stronger then plywood but all best off when wet-. Also nailing wind resistance of shingles check which holds nails better against wind...

Consider 16" on center truss for a little more cost a stouter roof assembly then 2' on center. then compare to this 16" on center and 1/2" plywood verses 5/8".

Also consider viewing Mr. Fergusons? videos on drywall installation with truss different nailing floating wall to ceiling install of drywall,o to avoid trust lift damage different nailing - find this on Finehome Building web page- it real good!

RISurfer
Re: Which Roof Sheathing? 5/8 OSB vs. Plywood

Thanks for the recommendations. I will check out Mr. Ferguson's videos.

Sombreuil_mongrel
Re: Which Roof Sheathing? 5/8 OSB vs. Plywood

When we frame, it's always 5/8" plywood for roof decks. No OSB.
Casey

jkirk
Re: Which Roof Sheathing? 5/8 OSB vs. Plywood

we use both osb with clips and 5/8 t&g roofply... just depends on what is in the budget and what truss manufacturer has spec'd. i prefer plywood, it has much more holding power for roofing nails and if it gets wet it doesnt swell up and stay swelled up like osb does

A. Spruce
Re: Which Roof Sheathing? 5/8 OSB vs. Plywood
jkirk wrote:

and if it gets wet it doesnt swell up and stay swelled up like osb does

I've seen quite a few cases where OSB buckles between trusses or warps. Probably caused by water, but heat expansion takes it's toll as well.

jkirk
Re: Which Roof Sheathing? 5/8 OSB vs. Plywood

yup. if osb isnt properly gapped, when it swells and has no where to go because its installed too tight it will buckle

dj1
Re: Which Roof Sheathing? 5/8 OSB vs. Plywood

I would use 1/2" plywood (5 ply) at a minimum.

What I don't like is the 24" between trusses. Talk to your architect about placing more of them to make them 16" o.c - as TM suggested.

JLMCDANIEL
Re: Which Roof Sheathing? 5/8 OSB vs. Plywood

For 24" OC I use only 3/4" plywood.

Jack

RISurfer
Re: Which Roof Sheathing? 5/8 OSB vs. Plywood

Thanks for the replys. I'm sticking with the plywood.

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