Tanking is a term that refers to damp proofing walls retrospectively by creating a complete water-impermeable barrier covering the entire wall. It is usually employed as a remedial method in situations where there is no access to the external wall of the structure, such as in basements and cellars.
If you have damp problems in a cellar or basement, or are considering a basement conversion and are concerned about possible damp proofing issues, please contact us. We have over 40 years of experience and work with many clients in this field including Bristol City Council, housing associations and landlords.
Methods of tanking can be divided into two main types. The first is by the application of a damp proof membrane (DPM) to the interior wall. This method in itself can be split into two types. The first of these consists of fixing sheets of polypropylene membrane to the wall with special membrane clips. The separate sheets are bonded with tape to create a complete seal and the membrane is then plastered over.
A DPM for tanking walls may also come in liquid form as a two part epoxy based membrane. This is applied directly to the underlying brickwork or masonry in two coats. The resulting waterproofed surface may then be rendered, plastered or painted directly.
The second main type of tanking is referred to as cementitious tanking. Cementitious just means that something is like, or pertains to, cement. With cementitious tanking, the wall of the structure is stripped back to the base material and then re-rendered with several coats of sand / cement render mixed with special damp proofing products. Cementitious tanking is normally used where the likely ingress of water is considered to be less than something that would require the fitting of a DPM.