How to Lay Ceramic Floor Tile Under a Toilet
One complication with tiling a bathroom floor is that you have to remove the toilet and cut the tiles around the toilet drain. The good news is that the toilet base obscures the tile edges, so perfect cutting is unnecessary. Use tile nippers, akin to pliers, but with curved, sharp claws at the ends instead of flat grips. You use them to break off chunks of the tile into the shape you need.
1. Locate the water valve behind the toilet and turn it off by turning the handle clockwise. Use your wrench to remove the water line from the toilet and to remove the bolts in the toilet base that attaches it to the floor. Flush the toilet several times to make sure it’s empty and then lift it straight up and move it out of the bathroom, exposing the toilet drain in the floor.
2. Divide the bathroom floor into four squares, with two intersecting lines, using your chalk snapline. Tile the bathroom floor starting at the intersection of the two lines, spreading down thinset mortar with a notched trowel and pressing the tiles into place with spacers between them. Build out from the middle toward the walls in a grid pattern, laying all the full tiles that will fit. Leave the area immediately around the toilet drain open.
3. Let the tiles set overnight.
4. Lay tiles loosely over the toilet drain, lined up with the grid on the rest of the floor and evenly spaced. Use a pencil to draw a curved line on the face of each tile just outside the position of the toilet drain beneath it. (You will can judge the position of the drain from the points where it’s visible in the spaces between the tiles.)
5. Use your nippers to chip away the tiles along the lines, using small, firm “bites” from the claws to break off the pieces, until you’ve chipped each one all along the curved lines. Don’t worry if the lines aren’t smooth and perfect, as they will be covered up by the toilet.
6. Spread mortar around the toilet drain and set the cut tiles in place there. Cut and set any other partial tiles that have to be laid around the floor (such as near the walls). Let the tiles set for a day.
7. Pull out the spacers. Use a grout float to grout the whole floor, pressing the grout into the spaces and pulling it of the tile face. Sponge off any remaining grout. Let the grout set for two days before re-installing the toilet. Run a bead of caulk around the base of the toilet, where it meets the tile.