Ceramic tile provides a beautiful and decorative surface, and functionally it provides a surface that is not affected by water. However, this is not to say that tile delivers a waterproof assembly. What it can do is protect those areas which are vulnerable to water damage—when installed properly.
Around residential bathtubs in many parts of the country, the building code requires the ceramic tile to extend beyond the wet area a minimum of two inches. This includes the vertical area along the face of the tub, in order to protect the adjacent surface which is usually gypsum wall board. While this area should not normally be subjected to water, it can occur.