Would you recommend the installation of a water proof membrane on shower walls?

Hello Paula

Should the wall surface you are tiling onto be constructed of either plaster or plasterboard then to protect from water damage yes, a waterproof membrane would be required.

As a product suggestion for you, Mapei UK produce a product called Mapelastic Aquadefense, this product is very easy to apply, simply like emulsioning a wall. Should you require further help or information on this product please call our office on 01283 730388 and ask for Becky.