Tiling onto differing substrates - bathroom

[Ugh!]

I will soon be tiling the bathroom and would like some advice as to how to tackle an inside vertical corner, one side of which is plasterboard, the other plastered stone.
Up till now the walls have been 'papered' using Vinyl and after a year or so wrinkles develop in the extreme corner due, I assume, to uneven expansion of the two surfaces.
When I tile this area I guess this uneven expansion will cause the grouting/adhesive to crack. I would appreciate any suggestions or advice on how to get around this problem ?

 

[Nestor_Kelebay]

Well, I've tiled over 22 bathrooms in my 50 years, and my guess would be that any differential movement between the front and side walls on your bathtub is due to movement in your house as a whole, rather than differential expansion of the drywalled and plastered walls in your bathroom.

What I'd suggest is to CAULK your vertical corners with white mildew resistant silicon caulk instead of using grout in those corners.

And, when setting the tiles, it's best not to cut the tiles to fit tightly together in the corners. it's better to allow a gap between the tile on one wall and those on the other for the grout to firmly root itself in.

And, if you find that the grout in the vertical corners does crack, then replace that grout with white mildew resistant silicon caulk to provide a waterproof leakproof corner on your tiling.

 

[joe-90]

It's never been recommended to grout corners. It is always better to use silicone.


joe

 

[Ugh!]

Thanks for the replies.

The house is about 200 yrs old and appears to be built onto bedrock so I don't think it is settlement. The walls are constructed from slate stone (scrap from the local quarry - Wales) and are virtually 'dry walled' in that there is very little lime motor between the stones.

I'll use silicone in place of grout for the vertical corner fill as you suggest.