Sealing the plaster in shower before tiling?

[zenonithus]

Hi all,

I did a search on this and it seems most of the questions are in regards to plasterboard. I have solid (clinker) walls in my shower area. Once old tiles are pulled off I will give the walls a skim. Though do I need to waterproof the plaster with some sort of application before tiling? Or should pva be enough? I'm concerned with water soaking through the grout. cheers

 

[blup]

Provided the plaster is sound and dry I don't seal it.

You can get epoxy based grout that is water proof as used in areas of total immersion like swimming pools.

Otherwise seal it as you would plasterboard.

Blup

 

[bobasd]

no need to skim if the block walls are in good condition after the tile and adhesive is cleaned off.
dont use pva in wet areas. you could use sbr.

 

[zenonithus]

Cheers guys. So no PVA? interesting. I've not heard of sbr, cheers will look that up. So are splashes of water on the grout generally ok and wont affect the wall too much?

 

[opps]

PVA should not be used when tiling. Period.

The moisture in the adhesive can reactive the PVA, and if, further down the line you have water ingress, the PVA may result in the tiles falling off. SBR (Styrene Butadiene Rubber) will deal with the potential "suction" issues without the risks of it coming away from the surface, even if you have a leak. That said, a leak in the wall may blow the plaster and I am assuming that you are using a cement based adhesive that doesn't go soft when wet, ie one that doesn't come out of a tub.

 

[zenonithus]

Thanks for the advice oops. What products are SBR based? I couldn't find any online.

 

[opps]

search for "SBR primer".

https://www.google.co.uk/search?saf....0...1c.1.64.psy-ab..0.2.199....0.v9MdVxZAgDk

5L is about £20, the smallest I have seen is 1L. Thin it as per the instructions.

 

[zenonithus]

Great, thanks. Will look that up.