ROCKCOTE Polymer Render Grey is a flexible acrylic based coating for use on substrates such as fibre cement and painted substrates where tolerance to movement and good adhesion must be considered. ROCKCOTE Polymer Render Grey requires no on-site additions and can be built up to 4mm coats for substrate levelling. ROCKCOTE Polymer Render Grey sponges to an attractive coarse finish and is ideal for being overcoated with ROCKCOTE top coats.