Wilko Damp Seal White 750ml eliminates stains on damp interior walls & ceilings*. It helps to stop discolouration on walls affected by damp penetration, & can also be used as a primer, sealer or finish. It dries to a matt, even-tone finish in 16-24 hours, perfect for overpainting with your chosen colour. The contents of this can will cover Approx. 3 square metres (actual coverage dependant on the surface).* Although suitable for use over damp, this product does not replace the need to repair any structural faults that allow damp to penetrate into the fabric of the walls.