New Standards

The potential and, some would say, current seriousness of the situation has prompted the European Commission (EC) and the International Standards Organisation (ISO) to produce performance standards for liquid applied waterproofing systems for use beneath ceramic tiling. The EC has in fact awarded a mandate to the European Organisation for Technical Approvals (EOTA) to publish a harmonised European Technical Approval Guideline (ETAG), the scope of which covers watertight covering kits for wet room floors and/or walls. This will include details adopted not only for tanking the base structure but effectively waterproofing any joints, internal angles (wall to floor joints), pipe penetrations, gullies etc. As a harmonised mandated document products conforming to the ETAG will be subject to CE marking regulations.

Ceramic tiles, adhesives and grouts are not normally part of the kit, similarly for the pipes and floor gullies themselves. The waterproofing tanking kits normally include components such as a liquid applied coating material and reinforcing meshes, strips or fibres used in the whole system or partially in the corners and around penetrations. In normal use conditions the tanking membrane and associated components must be able to resist stresses caused by movement of the structural elements and resist the influence of water, temperature variations and the alkalinity of ceramic tile mortars. The ETAG is based on an “assumed intended working life” of the kits of at least 25 years.

Installations subject to damp and wet conditions are usually divided up into three distinct areas of exposure to water, namely;
a) those in high humidity areas, e.g. kitchen
b) not immersed in liquid but subject to occasional wetting e.g. bathrooms
c) not immersed in liquid but subject to frequent wetting e.g. public showers
In most cases the liquid is likely to be mains water but in some circumstances it could be salt water, contaminated water, water treated with additives or even an aggressive liquid other than water. Due to the varying degrees of exposure from splash contact and condensation to the full force of a power shower directly onto the tiled wall, the correct choice of adhesive and grout is essential, coupled with the inclusion of a properly applied and detailed waterproofing membrane system.