Mixing aquapanel with plasterboard

[Hotwire]

Is it ok to mix plasterboard and aquapanel in either of these ways

1: Along the same wall like this, wall needs say 3 sheets of board. First sheet normal plasterboard then next two sheets aquapanel.

2: Wall needs the same 3 sheets but is going to have a double skin of boards, like so. First layer of boards normal or water resistant board, overplated wiith 1 normal plasterboard then 2 aquapanels.

I ask this question because i though cement based stuff caused a problem with plaster. Example, needing to put primer on skimmed plaster walls before using cement based tile cement. Or have i got this wrong.

 

[Beefcake daddy]

Two of the walls in my bathroom were combinations of aquapanel & 12.5mm plasterboard, been no problem at all.

 

[Hotwire]

Ok thanks, looks like i am not going to be able to use aquapanel due to there being 2 skins going on the wall. I spoke to Knauf technical today and was told that aquapanel needs to have an air gap behind it, which of course wont be there with it being screwed on top of the first skin of plasterboard. I never knew that, good job i asked. I was gonna put 2 sheets of aquapanel alongside i sheet of ordinary plasterboard, so when i read your reply i thought great no problem doing that. I was really uncertain though over putting it on top of plasterboard. One thing i dont get though is why you need to have an air gap behind aquapanel i thought it didnt allow water penetration.

 

[Mudster]

Aquapanel is a waterproof board, but it's not a waterproof barrier.

This is a common misconception.

Why are you layering the boards?

Can you not use studwork to make up the depth difference.

Plaster needs to be primered because there is a chemical reaction that can occur between the adhesive and the plaster, this doesn't apply to plasterboard.

Don't skim plasterboard before you tile, it's waste of time and money and derates the weight you can fit to it.

 

[Hotwire]

The aquapanel thing has got me confused Mudster, so does aquapanel let water through. The reason the boards are being layered is thats the way they originally were, in fact there was 3 layers of 12.5mm board. I had posted on here asking why the builders had used this many layers some time back. The general concensus was maybe for strengthening or sound deadening or both. Im a bit of a belt and braces man so im going for the 2 layer. Even without the extra skin the wall has got rockwool as sound deadening so there wouldnt be much of an airgap anyway, am i right thinking that. The wall will not be getting skimmed the tile,s will go straight on. I was first going to prime with bal-APD is this not necessary, i will be using a cementiuos adhesive.

 

[Mudster]

Aquapanel still needs to be tanked to become a waterproof barrier, it's advantage is it is completely unaffected by any moisture or water penetration.

No need to prime Aquapanel, it's desgined to be tiled on.

Prime the plasterboard and any plaster though, it gives you much more open time (adjustment time).

All the layers sound like overkill, still I'm all for a bit of overkill.

Overengineering never does any harm, it's the underengineering that causes the problems.

 

[Hotwire]

Thanks Mudster, that clears the aquapanel and waterproofing up. Even if i went the single skin route though is there still gonna be a problem with aquapanel requiring an air gap when there is rockwool insulation in use.

 

[Mudster]

Not quite sure what that gap is for, did Knauf enlighten you on that point?

 

[Hotwire]

They were saying something about a airduct or such, I will give them another call tomorrow and clarify if i get the chance. My brains have turned to sawdust with having so much work to do in the bathroom. Im gonna make a couple more posts in building forum, one over a snag ive hit today regarding water damage to a joist under the bathroom floor and another over wall insulation. Will i ever get this bathroom finished