Can I tile over tanked gypsum?

[Toastandjam]

Hi - for some reason, my builders used plasterboard for the walls around the shower and bath, and then skimmed it with gymspum.
I've since been told that plasterboard is a big no-no in a wet area and that gypsum can't take anything above 25kg per m2.

I can't install backeboard on top as it will eat up the space around the bath, so what do I do?

I was going to tank it and get tiling, but now worried that this isn't feasible?

Thanks.

 

[foxhole]

Shower panel ? More waterproof than tile.

 

[ajrtd]

I have tiled onto mapei

 

[Toastandjam]

@foxhole - not really what I want unfortunately - is it possible to tile onto tanked gypsum?

 

[ajrtd]

Yes.

 

[Toastandjam]

I have tiled onto mapei

...on top of gypsum, on top of plasterboard?

 

[ajrtd]

On to gypsum plaster

 

[Toastandjam]

On to gypsum plaster

and I'm guessing there were no issues? So it is doable?

 

[ajrtd]

No. Make sure you use that tape and tank below baths, sinks and showers.

 

[simplesteve]

Of course you can tile onto Gypsum.
1st coat with SBR : water 1:5. Second coat 1:3

 

[Toastandjam]

Of course you can tile onto Gypsum.
1st coat with SBR : water 1:5. Second coat 1:3

There's a primer that comes with my Mapei tanking kit - do I just use the one coat and then the tanking liquid?

 

[simplesteve]

Yes. The ‘two coats’ was for tiling straight on - no tanking.