DURO MASTIC™ ACS is a liquid applied acrylic membrane which, when reinforced and fully cured, forms a flexible waterproof lining for showers and other wet areas. DURO MASTIC™ ACS forms a waterproof lining to most building materials including reinforced concrete, cement render, water resistant plasterboard and fibre cement sheet flooring etc. The surface must be firmly fixed to manufacturers directions, free of protrusions, dirt, oil and other contaminants and surface must be dry.