Plastering on top of liquid tanking

[DIYz]

Hello

I’ve got a plastered room (roughly 1.6m x 1.8m) that I want to turn into a shower room but no window so even the areas outside the shower will get quite wet

Was thinking of getting tanking kit (such as Mapei Shower Waterproofing Kit) and tanking whole room, then tiling shower zone only, but plastering the ceiling and rest of the room, then painting with a bathroom waterproof paint. So my question is can I plaster over a tanking kit? Or can I paint straight on to it but I want a smooth finish so think plastering is best?

 

[tell80]

Whats your definition of a "shower room" - an enclosed shower in a room or some kind of wet room?

FWIW:
Wet walls eg tiled wet walls are rendered in a 4:1 mix of sand and NH lime, dont use gypsum.
You will need a powerful extractor and a way to hard duct it out of the building.
Is there any existing damp in the walls or floor?

Your question best in plasterers forum or tiling forum?

 

[DIYz]

Thanks tell80 for the quick response.

It’s a shower in a room, with a standard shower tray not a wet room, just not much natural ventilation so will have a level of wet in there, We have put a very good centrifugal extractor fan in and dropped ceiling in adjacent room to put solid ducting through and vent outside on the closest straightest run possible.

No existing damp, but the walls are complex mish mash of surfaces: part of the room has stud walls (moisture board) part is already plastered brickwork and part is a breeze block closed up doorway which has no render or plaster applied. We were thinking to tank it all and skim over tanking kit then use 4mm Marmox boards in shower area. Bathroom paint outside shower area

 

[tell80]

Thats great, you seem to be ahead of the game.
4mm is very thin, maybe up the thickness a few mm's esp if you are using the huge tiles that are now in fashion?
Wet areas should be tiled not painted.
Perhaps take advice from the painters forum ref best paints for non tiled areas & the plastered ceiling.
Also contact Mapei for a heads up.