Wedi Sanoasa Benches are much quicker and easier to install than metal tray or concrete seats. Plus, they bond well to thinset mortar and are 100% waterproof due to the CFC-free extruded polystyrene closed cell foam core. These benches will not cause efflorescence, discoloration or waterproofing issues that often occur with products requiring mortar fills. Wedi Sanoasa Benches do not require additional blocking installed in the framing because their mounting brackets are fastened into existing wall studs.