is half inch OSB satisfactry for roof deck under asphalt shingles

floridagramps1

In the Brooder
8 Years
Dec 13, 2011
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My first roof.........buying shingles today.........debating about OSB which I have for roof deck...........my roof will have 18 inch overhang at eves and gable end...........do you think I need to add drip edge

thanks
 
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from Long Island!
OSB turns to junk when it is subjected to constant moisture...
It should be OK as long as it is kept dry, so that drip edge may not be a bad idea.
Good luck with it!
 
IF you have a lot of snow,
and IF your roof slope is minimal,
and IF your rafters are centered greater then 16",
then NO 1/2" OSB will not work.

IF you don't ever have snow,
and IF your roof slope is at least 3/12,
and IF your rafter are at least on 24" centers,
then YES 1/2" OSB will work.

1/2" OSB will have a lot of "bounce" to it when you try to nail the shingles on. You might want to rent a stabler.

A YES on the drip edge molding.
 
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Depending on the sq footage of the roof and any possible weight that may be put on it like heavy snow or walking on it, 1/2" is fine for smaller roof's but if it is of decent size then 5/8" is the prefered thickness, place your studs at 16" ctrs, and yes if your going to shingle it OSB is great no problem like it was mentioned earlier it's used on millions of homes. A drip edge is a must IMO it protects and will make your roof edges last longer when trimmed in a 1"X 2" strip then a put on the drip edge.
 
If your trusses or rafters are spaced at 24", you might consider the H clips. These clips create the proper spacing for the product on 24" centers. Cheap. They sell them in small qualities too. http://www.homedepot.com/h_d1/N-5yc1v/R-100375081/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

Again
, there are millions and millions of home with precisely that combination, trusses on 24" o.c., 1/2" OSB and shingles. Might easily be MOST of the house built in the last 30 years with shingles. Plywood is expensive and the durability and weathering ability of it isn't any better. If plywood gets wet, it will delaminate and rot in a heart beat too.

Honestly, as far as "lasting" or holding up over the years, We've got OSB roofs now over 30 years old with no issues whatsoever. If a roof leaks or ice dams and backs up water, nothing, no product is going to hold up to that. Shingles work best, as stated earlier, on a roof of 4/12 and steeper. Shingles are not recommended on flatter roofs.
 
I have used osb for all uses around house chickens houses and all. As long as you protect from water you will be fine. We have it on deer stands in with open on the walls but is painted with sprayer every yr or so to make it last longer. Just do the tar paper and then shingle it and you will be fine. it will last many many yrs.
 
3/4" would be better. Like has been said there are a lot of factors involved. and 1/2" is not standardly used on roofs, often used on walls.
 

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