OSB vs Plywood for Roof

[WVH1977]

Is OSB just as good as plywood for a roof on a new house? Also, would y'all be ok with 24" on center trusses or rather have 16" on center. Is 24" OC going to cause issues down the road? Is it worth the extra coin to go 16" OC with plywood vs the 24" OC with OSB?

Thanks in advance for any responses.

 

[Deere Dude]

24 oc with 1/2 -osb works with shingles and drywall. but, 16 OC is better.
Depends on code in area but 24 works. Never had any problem with osb even though I was hesitant doing my first house with it.

 

[Rustyiron]

Richmond VA with (virtually)no snow load, sure, but don't forget the "plywood clips".

 

[RNeumann]

Truss packages are all engineered for span and sheathing thickness. No issues with 24” OC if it has been engineered that way! If you are concerned Simpson makes a little clip called an H1. It can be had in 1/2” and 5/8” if I recall. That will help with sheathing.

OSB and plywood is like Ford vs Chevy- just not as old. The glues have improved enough in OSB that it’s stable and does fine with moisture. Plywood obviously has a long history and does good with moisture.....until it doesn’t. When you get a little delam you will see that in the roofing. That said my current roof has plywood- I wasn’t the contractor and that was his choice. Everything else on the house is OSB- go figure!

 

[Gary Fowler]

Seems I read somewhere that OSB is actually stronger than plywood given same thicknesses. OSB is all I ever see used on roof sublayer.

As for spacing, I would go for 16" O.C. An extra truss every 4 feet isn't going to cost a lot more $$ unless you are talking a HUGE building.

 

[/pine]

Most residential trusses are designed for 2.0' OC installation...plywood clips are usually required for sheet decking 1/2" or less...(clips not required for 16" OC trusses/rafters etc..)...

With OSB there can be less waste due to no grain orientation...OSB is less friendly than plywood for marking and cutting cleanly...

16" OC framing makes for flatter ceilings...Often with things like veneer plaster ceilings with 2' OC trusses are stripped with 1x3s etc. on 16" oc...

 

[Tractor X]

24" requires plywood clips and drywall can get wavy without blocking. it doesn't cost that much more going 16 vs 24 oc.
when OSB 1st came out we called it "other $hits better"... still call it that today!
lm stick building my house with 3/4" wood decking, ice/water shield and 26ga metal... go plywood!

 

[stuckmotor]

A friend of mine built a porch onto his mobile home using rafters on 24" centers. Pretty soon, he got a cease and desist letter from the county. The building inspector wanted them closer together. I never heard how things worked out.

 

[Industrial Toys]

I only use plywood. I see OSB as garbage, but realize it has its place in the world and does a good job. I have done several outbuilding roofs, and the plywood is so much nicer to look at.

 

[aczlan]

I only use plywood. I see OSB as garbage, but realize it has its place in the world and does a good job. I have done several outbuilding roofs, and the plywood is so much nicer to look at.

From what I understand, the advantage of using OSB for roofs is that a smaller/thinner "chip" blows off of the back when you put a nail through it vs plywood, as such, with 1/2" plywood, you may have 3/8" of thickness where the nail goes through for it to grip whereas 1/2" OSB still has the full 1/2" or at least 7/16" for the nail to grip.

Aaron Z