FAST-FLEX is a fast setting floor levelling compound, which is recommended for application over a comprehensive range of floor surfaces. This includes tamped or worn concrete and sand/cement floor screeds, as well as non-porous floors such as mastic asphalt, plywood and mildly abraded power-floated concrete. It is particularly suited for installation in conjunction with heated sub-floors and can readily accommodate most types of wire-based sub-tile heating systems.