Slanted and Round Notched Trowels 28x13cm 6-15mm (select option)Slanted and Round Notched Trowels The slanted and rounded notch provide the following advantages. When placing a tile on adhesive spread with a slanted ridge, the ridges overlap and collapse to provide superior adhesive coverage on the back of the tile vs. a standard notched trowel. Superior adhesive bonding also increases the efficiency of under floor heating systems since it removes air pockets which inhibit the transfer of heat to the flooring.