Length of screw in drywall+OSB wall

[AochF]

Hello

A small question regarding mounting things on walls.

In our walls, there is a 13mm plasterboard + 11mm OSB.
How long should the screw be to hang heavier items on these walls? Is it sufficient if 24 mm of the screw is in the wall even if the innermost part of the screw is then the tapered tip? A plasterboard itself is quite strong and can handle quite a bit of weight as long as it is properly mounted. Most things you put up can technically be mounted even in plasterboard. So can the OSB be seen as an easy way to secure the screw?

The advantage of a 24 mm screw is that you don't have to worry at all about what is behind the boards. Most of the time, it is just insulation behind, which doesn't matter if a screw goes into it, but if you're unlucky, there might be something electrical, water or ventilation-related.

Or should you have a screw that goes through the OSB board so that the screw portion in the OSB board has full diameter?

How much difference do you think there will be in strength between the different scenarios?

 

[FredrikR]

Hi

A small question regarding mounting things on walls.

In our walls there is a 13mm plasterboard + 11mm OSB.
How long should a screw be to hang heavier items on these walls? Is it sufficient if 24 mm of the screw is in the wall, even if the innermost part of the screw is the tapered tip? A plasterboard in itself is quite strong and can handle a considerable amount of weight as long as it's properly installed. Most things you put up can technically be mounted even on plaster. So can the OSB be seen as a simple way to anchor the screw?

The advantage of a 24 mm screw is that you don't have to worry about what's behind the boards at all. Most often, it's just insulation behind which does not matter if a screw goes into, but if you're unlucky it could be something electrical, water, or ventilation-related.

Or should you have a screw that goes through the OSB board so that the screw part in the OSB board has full diameter?

How much difference do you think there will be in strength between the different cases?

Longer than 24mm is probably good.
What you fasten takes part of the screw's length.

 

[Rickard.]

I have no numbers but for the best strength, the entire tip of the screw (usually 10mm is said as a universal rule) must go through OSB and the difference is definitely noticeable. Of course, you can still hang lighter items without the best strength.

 

[tergo]

use drywall screws for wood 30mm

 

[AochF]

Thank you for the answers and tips!