I got this from the FAQ on the tile association ( they have in the last week removed the FAQ answers though :-( But they seem to correspond to part 4 BSI - even though i didn't see word Essential in there ? )
"Choosing shower or wetroom tiles
British Standard BS5385 is the Code of Practice for fixing wall and floor tiles. Part 4 of the Standard offers advice on fixing tiles in particular situations including wet areas such as in showers.
First check with your tile supplier that the tile is suitable for use in a shower and/or bathroom. Part 4 of British Standard BS538S, the Code of Practice for fixing wall and floor tiles offers advice on fixing tiles in particular situations including wet areas such as in showers. BS5385 states It is essential to tile onto an already water resistant background. Sand/cement render, dense concrete or water resistant tile backer board are ideal backgrounds. Plaster, plasterboard, timber and timber-based products such as MDF or plywood are absorbent and should be made waterproof by the use of a waterproofing or tanking system.
Note the word "essential" in the above paragraph. Failure to do this is the most common cause of tiling failures in domestic bathrooms. Tiling onto non water- resistant backgrounds is therefore in breach of the British Standard BS5385
An alternative to plasterboard or timber based products is tile backerboard which is an inert water resistant product.
Waterproofing systems can be painted on to or applied to an absorbent background. Most tile adhesive producers have a range of waterproofing systems that coordinate with the tile adhesives and grouts in their product ranges.
The tile adhesive should be a water resistant polymer enhanced adhesive meeting the requirements of BS EN 12004 for a D2 dispersion adhesive or C1 or C2 for a cementitious adhesives and the tile grout should be water resistant, meeting the requirements of BS EN 13888.
Tiles should be fixed using the solid bed method, i.e. ensuring that there are no voids beneath the tiles. The joints between the tiles should be filled using a water resistant grout.
Special attention should be paid to sealing the gaps between the base of the tiling and where the tiling joins the base of shower units or bath and penetrations in the tiling (e.g. shower fittings), using a good quality antifungicidal silicon sealant or a proprietary manufactured sealing strip specially designed for the purpose.
The shower should not be put into use until it has cured and is adequately dry
"Choosing shower or wetroom tiles
British Standard BS5385 is the Code of Practice for fixing wall and floor tiles. Part 4 of the Standard offers advice on fixing tiles in particular situations including wet areas such as in showers.
First check with your tile supplier that the tile is suitable for use in a shower and/or bathroom. Part 4 of British Standard BS538S, the Code of Practice for fixing wall and floor tiles offers advice on fixing tiles in particular situations including wet areas such as in showers. BS5385 states It is essential to tile onto an already water resistant background. Sand/cement render, dense concrete or water resistant tile backer board are ideal backgrounds. Plaster, plasterboard, timber and timber-based products such as MDF or plywood are absorbent and should be made waterproof by the use of a waterproofing or tanking system.
Note the word "essential" in the above paragraph. Failure to do this is the most common cause of tiling failures in domestic bathrooms. Tiling onto non water- resistant backgrounds is therefore in breach of the British Standard BS5385
An alternative to plasterboard or timber based products is tile backerboard which is an inert water resistant product.
Waterproofing systems can be painted on to or applied to an absorbent background. Most tile adhesive producers have a range of waterproofing systems that coordinate with the tile adhesives and grouts in their product ranges.
The tile adhesive should be a water resistant polymer enhanced adhesive meeting the requirements of BS EN 12004 for a D2 dispersion adhesive or C1 or C2 for a cementitious adhesives and the tile grout should be water resistant, meeting the requirements of BS EN 13888.
Tiles should be fixed using the solid bed method, i.e. ensuring that there are no voids beneath the tiles. The joints between the tiles should be filled using a water resistant grout.
Special attention should be paid to sealing the gaps between the base of the tiling and where the tiling joins the base of shower units or bath and penetrations in the tiling (e.g. shower fittings), using a good quality antifungicidal silicon sealant or a proprietary manufactured sealing strip specially designed for the purpose.
The shower should not be put into use until it has cured and is adequately dry