Thomsit XXL Xpress is a premium smoothing and levelling compound for most mineral subfloors, including cement/sand screed and concrete. Can be applied 0.5 to 20 mm in one application. Especially suitable for pump application. Roller castor resistant >1mm. Suitable for use over underfloor heating. Thomsit XXL Xpress is not recommended as a wearing surface. For interior use only.