Tiling Dilemma With Damp Wall Substrate

[mika_98]

Sorry if this sounds silly but I assume this means pre-drilling holes for the plugs and screws. Is that correct?

Been looking at No More Ply boards. The process on their site advises to use a 'Mega Strength Adhesive' on the joins. Is that an absolute requirement?

 

[Unused Account 1]

Keep away from all that ,just go in when ready to tile ,dont tke chances ,only as good as last job

 

[p4ulo]

Surely p4ulo u'd knock it out of plumb that way, u make sure it's bedded well, plumb and level it then mechanically fixed once dry?
Unless I'm doing it wrong?

I personally like to screw it down whilst its going off, ok - maybe doing it til it squidges is a bit much, but using my level at the same time I ensure its still flat once fitted.

 

[p4ulo]

Sorry if this sounds silly but I assume this means pre-drilling holes for the plugs and screws. Is that correct?

Been looking at No More Ply boards. The process on their site advises to use a 'Mega Strength Adhesive' on the joins. Is that an absolute requirement?

Yeah, you will need to pre-drill and rawl-plug before fitting the board.
Dunno about No More Ply boards, I'm a HardieBacker man meself, cos I get it cheap at Topps.

 

[Doggit]

Damp bricks take about a month per inch to dry out. If you're down to bare brick, then the normal way would be sand and cement with a waterproof render in it, but you should use a washed sand. The drawback is it'sll take a few weeks to dry. If you want to get on with the work quickly, then you could go for the Dryzone system. Not cheap, but you can get the plasterboard up in a day. Last method to think about, is to blackjack the wall to stop the damp coming though, batten the walls using tanalised timber, and stainless steel screws, then plasterboard - but make sure the blackjack goes on the ground as far out as the plasterboard will go.

 

[mika_98]

Thanks. What is blackjack?

If I use adhesive and galvanised screws to attach something like Aquapanel/Hardiebacker board, do I have to prime the bare bricks first?

 

[mika_98]

If yes to priming, what should I prime with?

 

[White Room]

Thanks. What is blackjack?

If I use adhesive and galvanised screws to attach something like Aquapanel/Hardiebacker board, do I have to prime the bare bricks first?

Bitumen type substance, used for tanking and waterproofing.

 

[Doggit]

Okay, back to basics. A damp wall will loosen off any normal adhesive you use to tile with, or soak into plasterboard that you dot and dab. The trick is to stop the damp coming through, so you either use the hardibacker/Aquapanel type board to seal the wall, but this will create damp air behind the boards. By using blackjack DPM (google it), or the dryzone system, is that the moisture is forced to evaporate to the outside of the wall. Having put the Blackjack on, you can then safely batten the wall (as adhesive may not stick well to it), and then use plasterboard - which works out pretty cheaply, and to be honest, stainless steel screws aren't really necessary, just an added precaution. I'd only use the adhesive and screw method on a drywall, not a damp one, as the primer isn't going to stop the damp coming through.