Mapei Keraflex Maxi S1 in Grey is a high-performance, deformable cementitious tile adhesive for porcelain, ceramic and natural stone tiles. Suitable for interior and exterior use, this tile adhesive is recommended for bonding large tiles with a bed depth up to 15mm. It can also be used for spot bonding insulation materials, such as expanded polystyrene, rock and glass wool, cork and sound-deadening panels.