Replies

1. 
   FrankB89 | Nov 17, 2002 12:14am | #1

   I personally avoid OSB on roofs simply because the withrawal resistance to roofing fasteners is less.  And I don't like working over it because it tends to be somewhat slicker than plywood.  And yes, it does tend to swell when wet, so along the drip edges, I've seen some guys slap some ext. primer before roofing.

   And if I WAS using it, I'd probably use 5/8 inch.

   (This, of course, is merely my own personal opinion).

    

1. 
   seeyou | Nov 17, 2002 03:42am | #2

   Must be a regional thing, but the only two thickness of osb available in my area are 7/16" and 11/16".

1. 
   bigwilly14 | Nov 17, 2002 04:17am | #3

   I have done quite a few houses with 1/2" OSB on 24" truss centers. We always used C-C-X or A-C-X plywood along the eaves and soffit. My only concern was that in a few years down the road the span may start to sag a little. But with 16" centers, you should not have to worry. But I highly recomend using plywood on the perimeter. It looks better after paint than OSB.

   Will

2. 
   FrankB89 | Nov 17, 2002 08:54am | #4

   It's sold as 7/16 or 11/16 but, due to humidity or other natural conditions, swells that extra 1/16" so that stock door jams fit flush. 

2. 
   gordsco | Nov 17, 2002 08:57am | #5

   Am I  one of the few who think OSB is not suitable for roof sheating?

   No, you are one of the many who think OSB is unsuitable for roof sheathing. Of course that is at 24" oc, at 16"oc there is no reason why you can't save a few dollars with OSB.

   Gordsco

3. 
   Nails | Nov 17, 2002 07:29pm | #6

   G. C. .....Haven/t seen plywood used here in central Illinois for years. Im so lod I can remember the old timers talk about using that damn "plywood stuff" instead of 3/4 board . I have seen or was around roofs that had 3/8" plywood  on 16in. centers with 3/8" ply clips and banks and realators are still making money on them.

1. 
   Boxduh | Nov 17, 2002 07:40pm | #7

   We are in 50 psf snow load country, and everyone seems to be using a 5/8 OSB t&g product for roof sheathing, when framing at 24" centers.

1. 
   r_ignacki | Nov 17, 2002 08:47pm | #8

   I worked in a Ryland Homes subdivision back in the '80s up in maryland, they used 3/8's plywood over trusses (2'oc), quite a few fatboys carrying shingles stepped right through the plywood.listening for the secret.......searching for the sound...

1. 
   stossel1 | Nov 20, 2002 08:14pm | #9

   When using osb, I always install plywood clips.