If customers want their tiled shower installations to meet BS Codes of Practice, the recommendations are clear. If customers want plaster board tiled without tanking I would ensure a written recommendation to tank the walls was made with a limited guarantee on their chosen specification.
BS 5385-4:2015 was published in October 2015 and Section 7 dealing with ‘wet and damp conditions’ now advises that in areas not subject to continuous water immersion but subject to frequent wetting, the basic structure
behind the tiles should be watertight.
In particular, BS 5385 Part 4.7.2.1.4 states the following should apply in respect of installations not immersed but subject to frequent wetting including wet rooms and domestic power showers.
a) The basic structure behind the tiles should be watertight and should be tanked.
b) Water-resistant materials should be used throughout. Plaster and plasterboard, would be unsuitable in frequently wetted areas.
c) The tiles should be solidly bedded so that voids behind them are eliminated as far as possible.
d) When the installation is tanked and water-resistant materials are used, cementitious grouting compositions may be specified.
e) Special attention should be paid to sealing the gaps between wall and base, particularly if the installation is on a suspended floor.
f) Where movement joints are subject to water immersion, water spray or splash, the joints should be sealed with curing sealants.