What is Tanking?

In construction, tanking refers to the practice of coating cellar walls to seal them against water - essentially creating a ‘tank’.

Basements often have problems with damp

Basements and cellars are more prone to damp than almost any other area of your home. By definition they are often submerged in a sodden environment.  

It has become increasingly popular for homeowners to convert basement space into living area. This is done to accommodate growing families, to give existing ones a little more space or simply to capitalise on the value of the home.

Unfortunately, most of Britain’s cellars were built before 1960. Liveability was not usually taken into account by earlier builders, who thought of cellars as nothing more than a storage area. Thus measures were not often taken to damp proof the understorey rooms.

Tanking is not as effective as adequate drainage

It is virtually impossible to create a totally waterproof wall, so drainage is the most important aspect of cellar-building. The easiest way to create adequate drainage is during the construction of the house. It is difficult and expensive to retroactively improve drainage.  

A swimming pool beneath your house

The materials used in cellar tanking are usually cement or bitumen-based membranes or liquids. These are applied thickly to all underground walls. The idea is to create a watertight seal around the entire cellar. Thus, the basement ends up resembling an empty swimming pool. Sometimes a sump or pump is required to deal with condensation or water build up.

Tanking or lining, what is the difference?

Tanking is a complete seal that needs to bond tightly to the walls and floor. This makes it troublesome on old, rough or ‘salty’ blocks.

Linings are dimpled plastic sheets that sometimes have an air gap between themselves and the wall.