How to use aqua boards behind tiles?

[Kaseyann12]

We have taken the tiles off our new build walls and majority of the plaster came with it so now can see the Joists. We have had pipe work installed ready for a shower above the bath! When going to buy tiles today we were told we need to use aquaboard behind the tiles which is fine we understand. Our problem is, what do we do next? Does all the plaster have to come off and the aqua boards fitted, can the aqua board go direct over whats there even though some plaster remains? Any help appreciated! First go at tiling a bathroom.

 

[angrypirate]

You can fix aqua boards direct to the joists. I would tidy up the plasterboard edges, add some noggins to 'catch' the edges of the aqua boards and screw the new boards direct to the joists.

Check the depth of the plasterboard 'probably' 12.5mm, you can buy the same depth aqua board as to avoid any ridges. If you only patch the areas without plasterboard I would advise liquid tanking the remaining plasterboard which is within the shower area, alternatively remove all the plasterboard within the shower area and replace with aqua panel.