It is a common misconception that tile and grout are waterproof. In reality, grout is porous and tile-to-tile joints are susceptible to water penetration, especially in a shower or tub area where there is frequent splashing. If you install tile directly onto a standard backer board without a waterproofing layer, moisture will eventually reach the wall assembly. Over time, this leads to the degradation of the substrate, the growth of mold behind the wall, and potential damage to the studs. To ensure a long-lasting installation, you must use a waterproof assembly behind the tile. This can be achieved through various methods, such as installing a waterproof membrane (like Schluter-KERDI) over the backer board, or using a dedicated waterproof foam board. These systems are specifically designed to be 100% waterproof, ensuring that any moisture that passes through the grout joints is stopped at the surface of the membrane and directed toward the tub. This protects your home's structure and prevents the need for costly future repairs caused by water damage. Do not rely on water-resistant sealers for grout; they are not a substitute for a true waterproof assembly.
Key considerations
- waterproofing behind tub tile
- is tile and grout waterproof
- tub surround waterproofing
- waterproofing
- tub-surround
- tile-installation