705 RAPID SET TILE MORTAR 20KG - RAPID20 Rapid Set Tile Mortar is a fast-setting thick or thin bed adhesive for bonding ceramic tiles to floors and most walls where same day fixing and grouting is required. Can be used internally and externally and bonds to most building substrates such as concrete, cement screeds and render etc. Conforms to BS 5980 as a type 1, Class AA adhesive, i.e. the adhesive is fully water resistant.