We use Zinsser Watertite Mould and Mildew Proof Waterproofing Paint, it provides a beautiful finish, guaranteed to keep water, mould and mildew out. It is a ready to use coating formulated to waterproof interior and exterior concrete, stucco, cement, cinder block and other masonry surfaces. Prevents the growth of mould and mildew on the paint film for 5 years. Ultra low odour solvent-based formula.