How to Troubleshoot a Shower Pan With Tile Leaks

Turn off the water to the shower by using either the shutoff valve hidden behind a panel on the wall where the shower is located or the main water supply valve, which is typically in the basement or a closet near the hot water heater. Turn the valve handle clockwise until it stops moving to shut off the water supply. Dry the tile floor with a towel to remove any water from the floor's surface.

Inspect all of the cracks in the grout. If you find less than five small cracks in the grout, apply the same color of grout used in the original grout job to small cracks or holes in the tile floor with a putty knife, sliding the edge of the putty knife into the crack to push the grout fully into the opening then smoothing the putty knife across the surface of the crack to remove any excess grout. Use a dry cloth to wipe up grout that gets on the tile surfaces before moving onto the next crack.

Remove the grout from the tile in the shower pan if the grout has multiple cracks in several areas, the cracks are larger than an inch or two, or the grout crumbles in any section of the floor. Place the point of a chisel or screwdriver against the crumbling grout or crack in the grout and tap the end with a hammer to break the grout. Remove the grout 1/2-inch at a time in this manner.

Vacuum up the old grout. Spread new grout over the tiles with a trowel until the spaces between all of the tiles are filled if there were multiple large cracks or the grout was crumbling. Let the new grout dry for 24 hours.

Apply waterproof sealer, whether you installed new grout due to multiple problem areas or simply repaired the grout. Waterproof sealer must be applied to the grout itself and to the caulking around the edges of the shower floor to prevent water penetration. If the shower floor is made of uncoated tiles, such as stone or terra cotta, apply sealer to the tops of the tiles as well to prevent water from being absorbed into the floor, which can cause shower pan tile leaks.