P20 Membrane (Ideal For Basement Flooring x 10 Rolls; Our P20 Membrane range of cavity drain membranes are high quality waterproof basement tanking materials giving a wide choice of stud height (drainage capacity) and plaster finish (dry lining or wet Plaster). 2m x 10m per roll For use on walls, floors, vaults and tunnels with minimal surface preparation required. Also suitable for external foundation waterproofing and to provide insulated dry lining for walls above ground level which may not be suitable for conventional plaster finishes.