Tile Is Only as Good as What’s Behind It

Anyone can stick tile to a wall. The difference between tile that lasts 30 years and tile that fails in five is everything you don’t see: the substrate, the waterproofing, the mortar coverage, and the movement joints. In Naperville’s 70s–90s homes we regularly tear out tile installed directly over greenboard or plain drywall — no membrane, no sealed seams — with black mold blooming behind it. The tile looked fine. The wall was rotting.

Our tile installations start with the right foundation: cement board or foam tile-backer in wet areas, a bonded waterproofing membrane on shower walls, sealed corners and penetrations, and mortar pans sloped correctly to the drain. Then tile — set with proper mortar coverage (no spot-bonding), consistent grout joints, and silicone (not grout) at every change of plane.

Where we install tile

• Shower walls and pans: the highest-stakes tile in the house. Full waterproofing system, flood-tested pan, then tile.
• Bathroom floors: large-format porcelain is the workhorse — fewer grout lines, easy maintenance, and it makes small baths feel bigger. Heated floor systems go under the tile, not over.
• Tub surrounds: tile replacing dated fiberglass or acrylic surrounds, with waterproofing behind it this time.
• Wainscoting and accent walls: tile wainscot with a proper cap, or a feature wall behind the vanity.
• Backsplashes and niches: the detail work — niche interiors, bench tops, and curb caps done in the same tile for a finished look.

Grout, Caulk, and the Details That Prevent Callbacks

The finishing details separate professional tile from handyman tile: grout chosen for the joint size and location (sanded for wider joints, unsanded for tight ones, epoxy where stain resistance matters), silicone sealant — never grout — at tub-to-tile and wall-to-floor transitions where movement happens, and expansion joints in larger floors. We also photograph the waterproofing before tile goes up, so you have proof of what’s behind your walls.

Can tile go over existing tile?

Sometimes on floors, if the existing tile is perfectly bonded and the added height doesn’t cause problems at doors and fixtures. In showers, we don’t tile over old tile — the waterproofing (or lack of it) behind the old tile is the whole point, and covering it up hides problems instead of fixing them. If someone offers to tile your shower over the old surround, that’s a red flag.