Insulated plasterboard

[Jack07]

I have a staircase in my house with 3 external walls (cavity, not insulated)

Because it gets cold, I'm always having mould in the corners which spread. I'm upgrading the radiator and was thinking of using insulated plasterboard under the staircase where the issue occurs.

I've used battens and foil before to good effect in other areas of the house but I have a bit of 37mm PIR plasterboard left over from a previous job. The insulation is paper not foil, but there is a foil layer between board and insulation layer.

I was hoping to stick the boards directly to the wall with board adhesive then mechanically fix them with plasterboard anchors.

Just wondering if I there's any problem with this or if I have to prep the wall first? There's no leak in the area, it's just the temperature changes and lack of air flow.

Thanks

 

[Mr Chibs]

You should be good to crack on.

You can also use screws and wedi washers (ebay) to hold it the wall.

 

[Jack07]

Thanks. Do Wedi washers sit flush with the surface of the board?

I wasn't going to skim the boards as they are mostly out of sight. I was going to fill and tape.

 

[mrrusty]

What I have done successfully just to add a bit of mechanical fixing to insulated PB fixed with adhesive, is to use red plugs and 5mm screws. You can drill a 5.5mm hole straight through the PB for the plug, tap the screw in with the plug on the end, tighten up, and the head on a 5mm screw is big enough to sink in to the PB and get a grip without pulling through, but countersunk enough for overskimming.

TBH a fair bit of the insulated PB in our house is just fixed with adhesive. You don't really need mechanical fixing as well, although I believe BR suggest it in case of fire and the insulation melts and the PB falls off the wall....

 

[Ivor Windybottom]

I overclad our ceiling using insulated plasterboard with bargain price squeezy glue and standard (long) plasterboard screws, no washers. All was well.

Half-tighten while the glue's wet, to squeeze it a bit and adjust to get it flat and where you want it. Make sure there's a big dollop of glue where each screw will go. Fully tighten the last bit by hand a few days later, when the glue has set so it's pushing back against you. They'll then sink in, get them flush without tearing through. You'll feel it and often hear the creak.

 

[noseall]

I was hoping to stick the boards directly to the wall with board adhesive

Have you thought about using foam fix?