Cavity Drain Membrane
Cementitious tanking systems work by holding back moisture with waterproof plaster. A cavity drain membrane system works differently, in that the moisture continues to penetrate the structure but flows behind the membrane and is channelled away to a drainage point. The membrane is fixed to walls and floors using special plugs and tape, and the walls can be plastered or dry lined afterwards.
The advantage of this approach is that it does not rely on the product to bond to the walls and floors, and there is no need to allow extra time for drying out before decorating.
Assured Preservations use Delta Membranes, which are certified by the British Board of Agrément and come with their own 30-year product guarantee.