OSB vs Plywood for Roof

[polkwrangler]

I had my house built in 2008,they used foiled covered osb for sheathing worked out great..lay foil side facing down though

 

[mikester]

OSB is used because its cheaper than plywood. End of story. The only thing worse than OSB is MDF. Builders would use 1/4 inch MDF if they could but that stuff has zero structural integrity.

The biggest problem with any of these materials is moisture. Plywood is the most moisture tolerant of the three, MDF the least. Wet plywood de-laminates. Wet OSB crumbles. Wet MDF turns to porridge. Plywood will have structural integrity, hold fasteners better and longer than OSB ever will. Wet wood is still stronger than wet glue.

Eventually all roofs leak.

If you plan on flipping the home or moving in the next 5 years use OSB because it’s cheaper. If this is your forever home go plywood and you will thank yourself later.

 

[Oldoak]

Everyone has their own preference and in many, but not all areas, a building code that must be adhered to.

On our new house that we had built just six years ago, I specified 2x6 trusses, 16" on center and 5/8" plywood for the roof construction. And 2x6 studs, 16" on center and 1//2" plywood for the exterior walls.

 

[newbury]

OSB is used because its cheaper than plywood. End of story. The only thing worse than OSB is MDF. Builders would use 1/4 inch MDF if they could but that stuff has zero structural integrity.

The biggest problem with any of these materials is moisture. Plywood is the most moisture tolerant of the three, MDF the least. Wet plywood de-laminates. Wet OSB crumbles. Wet MDF turns to porridge. Plywood will have structural integrity, hold fasteners better and longer than OSB ever will. Wet wood is still stronger than wet glue.

Eventually all roofs leak.

If you plan on flipping the home or moving in the next 5 years use OSB because it痴 cheaper. If this is your forever home go plywood and you will thank yourself later.

Unless you go with a quality OSB like AdvanTech and compare it to run of the mill big box hardware store plywood.

I've gotten plywood from Lowes and Home depot that delaminated slightly, then when I look inside there were massive voids. So on 5 layer plywood I would find a "decent" surface layer, a voidy second layer, etc. Sometimes a "knot" on the surface layer would line up with a void underneath.

OSB is solid when made and I've seen the AdvanTech sit out in the rain for months. But the darn stuff is HEAVY. Unlike PT plywood it does not get lighter with age.

"Old timy" OSB used to crumble quickly. Throw a fresh piece off the porch in the rain and it would crumble before it hit the ground

 

[fried1765]

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

That is a new theory for me!
In my opinion, OSB is only better on the wallet!
Cheap junk!!

 

[TMGT]

I recently had a lot of experience with OSB while building my shop, before building I also had my reservations with OSB from past experiences.
I will say there have been a lot of improvements to OSB over the previous stuff, and a decrease in plywood. I would put them about equal for modern 7/16-1/2 sheathing with the OSB being less expensive, also you have the advantage of consistent density with the OSB where you will hit voids with the plywood when nailing.

Only thing I dont like about OSB is cutting it (the sawdust gets everywhere and always in my eyes) and you have to be a little more careful with the corners/edges.

Then theres advan-tech, it's in a class of its own!

 

[Sawyer Rob]

Personally, I prefer plywood, there's no doubt it's better... Ply is better if the roof has a leak later and better with 24" rafter spacing for less sag ect...

That doesn't mean OSB won't work, but it has to have the nails set perfectly! Any nails going below OBS' surface and you loose a lot of the holding strength, not so much with plywood.

IF I had the money, I'd go with ply every time...

SR

 

[3Ts]

Then theres advan-tech, it's in a class of its own!

Agreed! But even if you specify that particular brand, the chance is good that the lumber yard will ship some other brand and claim it's just as good, but it's not. I've used it for sub-floor and it's better than anything else on the market.

 

[Tractor X]

Everyone has their own preference and in many, but not all areas, a building code that must be adhered to.

On our new house that we had built just six years ago, I specified 2x6 trusses, 16" on center and 5/8" plywood for the roof construction. And 2x6 studs, 16" on center and 1//2" plywood for the exterior walls.

well built house right there!!!

 

[nybirdman]

As far as sheeting;ZIP board is the "go-to" in our area.They make if for side walls and roofs.