Watch how to lay porcelain tiles, slabs, pavers and natural stone onto pre-existing external concrete bases. BAL's new Level Out external leveller helps level uneven or damaged concrete bases prior to tiling or laying porcelain or other tiles. BAL Level Out can be used from 2mm to 20mm in bed depth, and is ready to tile in only 3 hours. Tiles can be fixed with BAL Pourable One, a thick-bed pourable floor tile adhesive.