... roof tiles 1.30x20cmx4-6mm (12"x8") 2.lowest breakage rate 3.conform with ASTM406 & B.S.EN12326 standards slate roof tilesNatural slate roof ... firmness during either transport or installation process. SHOS roof slate tiles are of the lowest calcium content (less 0 ... floor tile,flagstone,stackstone,crazy mesh,stairs,mosaics,roof tile,quoins,culture stone, etc. natural slate roof tiles with cleft surface