What thickness of OSB or plywood behind drywall?

[Klicka]

If you plan to install plywood or OSB behind drywall, what thickness is typically used for OSB or plywood?

 

[pyro]

I usually use 11mm OSB.

 

[Klicka]

Another question.

Cheapy has an OSB board (11x1200x2440mm. Dimensionally stable). Since it is 1200mm wide, does that mean you should install them edge to edge without any gap?

 

[Nimajneb]

Another question.

Cheapy has an OSB board (11x1200x2440mm. Dimensional stability). Since it is 1200mm wide, does that mean you should put them edge to edge without spacing?

Putting them edge to edge is much better than overlapping them.
So the answer is yes.

 

[Amrich]

I usually leave a few mm between the OSB boards to give them room to expand a little. As far as I know, there's no disadvantage to this and it hardly creates more work. And I don't know if they are really fully 1200?

Don't forget to offset the joints
between gypsum and OSB. That is, no joints in the same place!

Sent from my GT-S5570 using Byggahus

 

[Ola78]

All wood-based panels behind gypsum are set with a 2-4mm gap to allow for some movement, just like Amrich writes. The OSB, plywood, and particle boards we use at work are at least 1198 mm wide. However, I'm not sure if that's standard or if ours are custom ordered that way.

 

[Klicka]

Is OSB attached with regular drywall screws or something else?

 

[pjodden]

The width is probably standard since all the boards I've bought have been 1198.

I always attach OSB with chipboard screws, ~30mm. I tried using regular drywall screws once due to a lack of alternatives, but they tended to break at the head.

Sent from my GT-I9100 using Byggahus

 

[covet]

I have used drywall screws 3.9 x 40 mm. They stick like a rock. Sure, the head can break off, but it's maybe one in 500. I think the head on chipboard screws is too small.

 

[Ola78]

Is OSB attached with regular drywall screws or something else?

At work, we staple all OSB, as it shouldn't take too long for us. But chipboard screws will probably be just fine if you don't have a pneumatic staple gun.

 

[Amrich]

I just built an interior wall with OSB + drywall. I used 30mm chipboard screws for the OSB. It held well and had no problem gripping the board even where it bulged slightly. I then secured the drywall with 40mm drywall screws in the studs. If you have OSB behind it, you don't really need to screw the drywall into the studs, so you can manage with shorter screws.

 

[mycke_nu]

I do the opposite where possible.

That is, attach the OSB with a few screws or even a few shots from the nail gun and then screw the drywall with long screws through both boards into the studs.

 

[Johan Gunverth]

All wood-based panels behind plasterboards are installed with a 2-4mm gap to allow for some movement just as Amrich writes. The OSB, plywood, and chipboards we use at work are at least 1198 mm wide. I don't know if that's standard or if ours are custom-ordered.

Byggelit’s chipboards are 1200 and should be mounted edge to edge AND glued on the short side according to the construction instructions. I use them myself.

 

[Mikael_L]

I do the opposite where possible.

That is, attach the OSB with a few screws, or even a few shots from the nail gun, and then screw the gypsum with long screws through both boards into the studs.

I _think_ that's a bit odd.
You're putting unnecessary strain on the joint of the gypsum screw's head -> gypsum board's paper. And any movement in the OSB boards due to moisture, heat, and the building's movement transfers to the mentioned screw joint. And suddenly the gypsum screws have gone through the paper and started to embed into the board.

NOTE, I have absolutely no other evidence for this other than my own thoughts on what could happen.
If you have walls that have held up well for many years made with this method, you have an empirical basis to stand on.

edit:
And as an answer to the thread's question:
I have used 11mm OSB. Screwed with 30-32mm chipboard screws.
Then 13mm gypsum with staggered joints against OSB, mostly screwed with 32mm gypsum screws, but some I've used 40mm - where I know there's a stud underneath, not because I really think it brings any real improvement, but just because it feels a bit reassuring, sort of.

I don't know if there is any other thickness of OSB?
If I had used plywood, I think 10-12mm something would have felt good, and if I had bought chipboard I think I would have chosen 12mm.

 

[Ola78]

Byggelits particle boards are 1200 and should be mounted edge to edge AND glued on the short side according to the construction description. I use them myself.

Hm, that does indeed sound very convenient, but I have never heard of these boards and how are they manufactured not to move?