Screw for OSB + drywall

[Mhellstrand]

Hello
The search function seems to be having some issues as I recall this has been discussed more than once here on the forum, but I can't find the right thread...

The questions are: I'm going to mount OSB + 6mm plasterboard at home on a couple of walls with studs.

1 Should I attach the OSB board a little "loosely" and then drive screws through both the plasterboard and the OSB?
2 What screws should I use and what dimension should they be?

Thanks
//M

 

[MathiasS]

What one SHOULD do is for someone else to determine.

I screw OSB into the studs with 40mm drywall screws and then screw the drywall into the OSB according to the drywall manufacturer's instructions. 30mm is enough for this. The seams of the drywall panels are offset.

 

[Lymmeln]

I used chipboard screws for the OSB, don't forget 2mm spacing between the OSB boards, I tapped in a couple of dyckert as spacing.

 

[barajag]

Hello
The search function seems to be acting up a bit as I think this has been discussed more than once here on the forum but I can't find it...

The questions are: I'm going to install OSB + 6mm gypsum at home on a few walls with studs.

1 Should I attach the OSB board somewhat "loosely" and then drive screws through both the gypsum and the OSB?
2 What screws should I use and what size should they be?

thanks
//M

If you want to hang something on the wall, you can use double-threaded screws for OSB, which you screw in fairly closely, cc20 in any case. When you screw the gypsum, it's good if that screw also goes through the stud, then you know it will stay in place.

I can never remember what the screw is called, Hilti has its own which works great but is expensive, I googled a bit and Danogips has one called Cresco F which is intended for floors but has the same function.

http://byggsystem.knaufdanogips.se/products/screws/index.html

 

[MathiasS]

If you feel the need to screw the plasterboard into the studs as well, you might wonder why you put up OSB in the first place.....

If you screw with regular cheap 40mm screws, the OSB will hold for anything you might want to hang on the wall. It is the attachment in the OSB that will be the limitation, not the OSB's attachment to the studs.

 

[barajag]

If you feel like you need to screw the drywall into the studs too, you might wonder why you put up OSB in the first place.....

If you screw with regular cheap 40mm screws, the OSB will hold for anything you might want to hang on the wall. It's the attachment in the OSB that will be the limitation, not the OSB's attachment to the studs.

Screwing the drywall into the studs was, as I mentioned, only good if you could do it, while you're at it, but as I said, not a necessity.

The other thing, regarding regular 40mm drywall screws, of course, that works too, but it doesn't grip as well as a double-threaded one, so my suggestion was if Ts planned to hang something heavy, it might be good to know that before starting and then decide how he wants to proceed.

Ps: On some large construction sites you are not allowed to screw OSB with drywall screws, but it depends on who is the material supervisor and foreman.Ds

 

[MathiasS]

But the type of screw you are talking about with an extra thread on it (like the cresco f you linked to) has nothing to do with extra strength - it's about countersinking the screw head.

 

[barajag]

But the type of screw you're talking about with an extra thread (like the cresco f you linked to) has nothing to do with extra strength - it's about countersinking the screw head.

It presses down/together the board better, (never becomes wild thread) but as you wrote, it also countersinks, the one I linked to is for flooring but they have the same function.

 

[Mhellstrand]

What is the reason for offsetting the gypsum board joints? (yes, I'm a "Åsa-Nisse" on this!!)

What one SHOULD do, someone else can decide.

I screw OSB into the studs with 40mm drywall screws and then I screw the drywall into the OSB according to the drywall manufacturer's instructions. 30mm is sufficient for this. The joints of the drywall panels are offset.

 

[barajag]

What is the reason for staggering the gypsum joints? (yes, I am "Åsa-Nisse" on this!!)

It becomes more stable and you avoid general joints for sound, etc.

 

[MathiasS]

For clarity's sake. The plasterboard seams are offset compared to the osb seams.

 

[Stommen]

Jumping in with another OSB question!

When installing OSB, should you apply caulk around the boards like you do with the first layer of gypsum to soundproof?

Can/should you also apply it around the electrical boxes?

 

[estwing]

one uses regular drywall screws with 2-layer screws on OSB.
if you want to hang something heavy on the wall, I wouldn’t choose OSB but regular construction plywood...
OSB is really a useless board that is pressed together with a lot of chips...
not exactly good to hang heavy things on.

the thing is that the first layer should be screwed almost as much as the second layer, meaning fully screwed...

screwing the drywall into the studs then makes me feel good in my head that it’s done but not necessary...
offset the seam as mentioned earlier...
regards
estwing

 

[MathiasS]

I think it's good to clarify what "heavy" is. 100kg is not heavy if you have more than one mounting point. I can hardly imagine anything that you would normally wall-hang in a house that cannot be hung on an OSB board.

 

[Stommen]

Here's what Beijer says about the hanging ability

http://www.beijerbygg.se/templates/BB_ByggradListItem.aspx?id=52659

Does anyone have an answer to my question?