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 a 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. The advantage of a cementitious tanking system is that it is vapour permeable. As the movement of water vapour is generally outwards - from the basement or cellar - this allows the room to breathe.