Q. What is meant by ‘Tanking’?

Submitted by: JA 

A. ‘Tank’ or ‘Tanking’ are words often used by the damp-proofing/waterproofing industry when talking about the application of a form of waterproof material directly onto the surface of a wall, floor or ceiling in order to prevent the penetration of moisture. This is usually in a below ground situation.

‘Tank’ or ‘Tanking’ are words that should only be used when a complete internal application of a waterproof material is being applied in a given area directly on to all of the walls, all of the floors and if relevant all of the ceilings i.e. at least five sides of a box. In other words it means the creation of a completely waterproof area (a tank) designed to keep water out. Cement based systems are usually used in a true ‘tanking’ situation. Anything less than a complete application of a waterproof material on to all masonry surfaces in a room is not ‘Tanking’ in the true sense of the word.

‘Tank’ or ‘Tanking’ are words that are very often misused. It is not unusual for a contractors to say ‘We will tank that section of wall’ whereas what they should be saying is ‘We will apply a waterproof material on to that section of wall’ - the reason being that they are only coating part of a wall – not a complete system. Some will use the term ‘structural waterproofing’ which is fine. This may seem rather petty but we are aware of a court case where a contractor lost because of the inappropriate use of the word ‘tank’.

Cavity drainage membranes are now widely used to create dry habitable areas in an existing below ground situation. On many occasions we have seen the misuse of the words ‘Tank’ and ‘Tanking’ when describing the use of these materials for this type of application. Cavity drainage membranes, when used in this way, are a sophisticated dry lining process. They are neither ‘Tanking’ nor ‘Structural Waterproofing’. Confusing isn’t it!