Fit Plywood as backing for Plasterboard

Onar · Post by **Onar** » Tue Oct 29, 2024 2:44 pm

Hi,

I am using Plywood as backing for Plasterboard.
5.5 mm Plywood
12.5mm Plasterboard

For Plywood, I intend to use only a few screws since longer screws on the Plasterboard will fully secure the Plywood.
Is any special preparation necessary before fitting the Plasterboard?.

Thank you.

stevei · Post by **stevei** » Tue Oct 29, 2024 8:37 pm

I think we have been here before. Last time you were going to use mdf and now 5mm plywood. Why? There is no need whatever to fit plywood under the plasterboard. You will be wasting your money.

Grendel · Post by **Grendel** » Wed Oct 30, 2024 8:28 am

Agreed the ply isn’t really necessary. What’s your reasoning behind using it?
I’ve seen it done on a couple of occasions. Once with a stud wall built with really very flimsy materials and the ply stiffened the wall ( restoration , architects don’t like to remove original material) and the other was in a kitchen (again old building) to give a wider chance of a secure fixing for units . In that case I’m sure it was 18mm ply and in the former it was thinner. It both cases the ply was properly secured with its own fixings .

dewaltdisney · Post by **dewaltdisney** » Wed Oct 30, 2024 8:53 am

I saw that Onar wanted to brace the wall as it might be flimsy. Rather than sheath it in plywood, extra noggins and corner braces would firm it up. The money saved on plywood should be spent on insulation to fill the void.

DWD

Onar · Post by **Onar** » Wed Oct 30, 2024 9:39 am

Yes, it was in my earlier post and I removed the laths as was advised. Thank you.

You were all correct, the laths would not allow a flat enough surface for the plasterboard.
Plasterboard structure has limitations when hanging items, so that is why settled on plywood instead of MDF.
I can get plywood at a much more attractive price.

Grendel · Post by **Grendel** » Wed Oct 30, 2024 12:05 pm

To be fair a ply skin is a decent way to stiffen a structure, I’ve also done it with floors gluing the layers as well as mechanical fixing and if you can get ply at a decent price that’s fine . It will make the wall thicker road small degree which probably isn’t a problem and it’s best not to have anything like pipe work joints in the wall because it’s a pain to get to if ever needed .