Anyone who has ever cleaned a bathroom knows the grout between the tiles is the most stubborn part to clean, and it traps odors. To combat this in c-store bathrooms, Henken suggests using rectified tiles for the floor. “Rectified” means that the tiles have been ground or sawed after firing in the kiln, which makes their dimensions more exact. Henken says rectified tile can reduce grout lines to as little as 1/16th of an inch, making cleaning grout less of a hassle.
Rectified tiles can be pushed closer together than conventional tiles.