RenderProof is an additive designed for use in sand / cement mixes following the insertion of a chemical DPC and in other waterproofing applications. It is common in a wall suffering from rising damp for salts carried in the water to concentrate in the wall. As the wall dries out following insertion of a DPC these salts may be deposited on or near the surface and can give rise to efflorescence. If salts are hygroscopic, damp patches may also develop when the ambient humidity is high. It is essential that a suitable replastering schedule is adopted following the insertion of a DPC. RenderProof is a vapour permeable replastering additive, designed to minimise the passage of liquid water through the pore structure of cement renders, thereby preventing the transfer of salts to the surface.