re shower tiling

[fred]

It depends on the surface you are tiing on. Flat bed adhesive is designed to create a waterproof seal between tiles and the background-ie plaster, etc. If you're tiling on a well sealed or waterproof background, it is usually unecessary to create a solid 'wall' of adhesive.

[Dave]

It's onto skimmed plasterboard (too late to change) - so maybe the answer is to have a flat bed and ripple the top.

Dave

[Nigel Molesworth]

Bollocks