Tile needs to be installed underneath the toilet. Because the seals on a toilet wear out, they need to be replaced. You know they need replacing when your toilet starts leaking from the bottom, along the pedestal.
By installing the tile underneath the toilet, you are able to remove the toilet without having to break up your tile, giving you access to change the seals and wax ring.
Before you begin tiling the bathroom floor, you will need to remove the toilet and put it in a safe place, away from the project site.
Removing the toilet
Shut off the water valve for the toilet. Flush it to drain out the water and remove as much of the excess water left in the tank as you can. This reduces the amount of water that leaks out when you lift the toilet off the floor.
Remove the nuts from the retaining bolts located in the base of the toilet. Put these in a plastic bag and set in a safe place. Lift the toilet straight up; do not “jiggle” the toilet loose. You should feel some resistance. This is the wax ring breaking which then allows the toilet to be moved.
Clean off any wax from the bottom of the toilet left by the wax ring and move the toilet to a safe place.
Tiling
Clean the area around the drain, taking great care not to allow any debris to fall into the drain. Around the drain is the retaining ring. You will tile up to the edge of the retaining ring.
Because the toilet will hide the tile edges around the retaining ring, you do not need to make round cuts for the tiles. Instead, you can align the tiles just as you do for the rest of the floor, cutting only to accommodate the general shape of the retaining ring. Do get as close as possible, though, to the ring itself.
Grouting
Grout the floor after the tile is installed. You do need to grout the area hidden by the toilet, but do not grout in the space between the tile and the retaining ring. You do not want grout adhering to it. The retaining ring anchors the toilet to the floor. Should you need to replace that part, you do not want grout around it.
Reinstalling the toilet
You need to install a new wax ring before reinstalling the toilet. Wax rings are one time use item. Place the new wax ring around the drain and without twisting or rocking it, apply gentle but firm pressure on the ring to secure it to the surface.
Set the toilet back into place. Gently lower the toilet, positioning it over the retaining ring and bolts. Replace the nuts. Turn the water valve back on and flush to fill the toilet.
Now if you need to replace the seals and wax ring for your toilet, you do not have to break up your floor. Merely remove the toilet, do the repairs, and replace the toilet.
