How to Lay Tile Over a Fiberglass Pan

Snap a chalk line that goes across the center of the shower pan in both east-west and north-south directions. This creates four equal quadrants on the shower pan, with the center of the pan marked by the spot where the two chalk lines intersect.

Slide the bottom flange for the drain pipe assembly into the drain hole. Place tape over the assembly so no mortar can enter the pipe and cause a blockage. If the drain hole is in the center of the shower pan, place a tile in each quadrant over the drain hole, and trace the outline of the drain hole onto the tiles before installing the bottom flange. Cut the tiles along the line with a wet saw.

Mix a batch of thinset mortar, following the manufacturer's instructions.

Spread thinset onto the shower pan in the center of the pan, covering an area about 1 foot square. Spread the thinset with the smooth edge of a notched trowel, then pass over it with the notched edge to create grooves in the mortar.

Lay the first tile into the thinset, lining it up with the chalk lines. If the drain hole is in the center of the shower pan, use one of the tiles you cut.

Place tile spacers next to the tile, then lay the next tile into the mortar, working out toward the wall in front of you. Continue laying tiles and tile spacers until you reach the wall, applying the thinset as needed. If you cannot fit a full-sized tile, leave that space bare for now. Install tiles onto the side and top lip of the shower pan as well.

Lay another row of tiles, starting from the first tile you laid in the center of the shower pan and working toward the side wall of the same quadrant. When the two rows are completed, they will be in the shape of an L.

Lay more tiles in the first quadrant until it has been completed, alternating the rows as you did with the first two rows.

Lay tiles in the other three quadrants, using the same method you used for the first quadrant.

Measure and cut any tiles you need to install around the perimeter of the shower pan, then lay them into position. Allow the mortar to set for about an hour.

Mix grout for the shower pan, following the instructions on the packaging.

Place the grout onto the tiles in the shower, beginning in the back of the shower. Spread the grout onto the tiles with a grout float, removing the tile spacers as you come across them. Completely fill the gaps between the tiles with grout by running over the tiles diagonally with the grout float, making several passes before moving to the next section. Allow the grout to set for about 20 minutes.

Remove the grout from the surface of the tiles by wiping them down with a damp sponge. Rinse the sponge frequently as you do this. Allow the grout to set for another 45 minutes.

Wipe the tiles off with paper towels to remove the hazy film from the surface.