BS 5385-1 Waterproofing Regulations and How They Affect You

With the latest codes of practice released in July 2018 for BS 5385-1 (wall and floor tiling in normal internal conditions) by the British Standards Institute (BSI), there has been a positive change in regulations overseeing works in wet areas.

Under the new revision, all substrates should now be waterproofed before tiling, even in domestic locations.

Why is Waterproofing Important?

A wet area is considered to be any wet-room, bathroom, shower area, steam room or any other location that is subjected to frequent water contact. Although these rooms/spaces tend to be tiled, the substrates the tiles are being fixed to (such as plaster, plasterboard, or some proprietary backer boards) are often moisture sensitive. The British Standards now advocate the use of tanking membranes to protect them.

Tiles alone are not enough to stop water from getting through to the substrate. It is a common misconception that cementitious adhesives and grouts are waterproof, however, most are only water-resistant. Cementitious adhesives and grouts are popular choices for fixing tiles, and their porous nature allows moisture to pass through. Over time, water is absorbed through the grout joints and adhesive bed, and then into underlying substrates.

If the substrate is unprotected, it can lead to damp and mould issues. As time progresses, this can even cause problems with adjoining rooms and/or cause tiles to de-bond which can become a costly situation to repair.

British Standards already supported waterproofing in commercial wet areas, but under the new BS 5385-1:2018 clause 6.1.1.3 for "Tanking", it will now also be recommended to waterproof domestic locations as well. So, whenever you're retiling a bathroom, shower, or other wet areas, remember to apply a suitable proprietary tanking membrane system first.

Not following the BSI guidance can become costly. With the new standards in place, you could be as accountable for repairs in domestic areas as you are for commercial locations. This not only includes the tiled wet area but adjoining rooms as well.

Here at the Wetroom Store, all of our tanking pastes/kits, tile backer boards and shower liners are suitable to comply with this regulation.