Basement Waterproofing or as it sometimes called 'Basement Tanking' or 'Cellar Tanking'
For centuries various methods of basement waterproofing have been tried; from bitumen paint, to 'stick on' sheets, to waterproof cement renders and coatings.
Such methods aim to produce a perfectly waterproof three dimensional 'tank', bonded to the structure, hence the name 'tanking' has become synonymous with the process of basement waterproofing.
However when the ground water is high, even minor defects in a 'tanking' system will be revealed, and it has become generally accepted that such methods are not reliable enough for today's standards. See 'Click to see animation of Tanking Failure'
ABOVE: EXAMPLES OF FAILED 'TANKING'.
More recently the 'cavity drainage method' has evolved adopting civil engineering principles whereby the outer part of the basement structure is allowed to 'leak' and an inner layer is protected from water ingress by virtue of a drained cavity, Although the term 'Tanking' is still often used to describe the cavity drainage method, strictly speaking it is not tanking, it is an alternative method generically distinct and different from tanking at the most fundamental level.
Cavity drainage is a lot more forgiving by nature as it does not rely on a bond between the waterproofing system and the structure, this allows the structure to move and crack without causing defects in the waterproofing and because there is no bond between the waterproofing and the structure, it cannot delaminate as a 'tanking system can.
However, early cavity drainage systems were not immune from problems of their own, in particular: -
- Efficient evacuation of water from below the floor membrane.
- Condensation occurring on the internal plastic surface of the membranes
- Clogging of spaces between the dimples of the more 'rigid' membranes
- Lack of post-installation servicing of the sumps and pumps which form part of the system
The founders of Advanced Basement Solutions have addressed all of these problems and in doing so have become industry leaders, changing the way that basement waterproofing is done. Key innovations include thermally insulated membranes to avoid condensation, underfloor channels and bespoke sump and pump systems with perforated sump liners which work together to reduce water pressure in the ground. Click to see animation of Drained Cavity System