Shower tile feels loose or sounds hollow when tapped

Symptoms

• Tapping the tile produces a hollow or drum-like sound compared to neighboring tiles
• Tile flexes slightly under light pressure
• Grout lines around the tile are cracked
• Occurs near the tub edge or a corner most often

Likely causes

• CommonWater intrusion breaking down the adhesive behind the tileLeaks through cracked grout or caulk let water reach the mortar or adhesive, weakening the bond over time.
• CommonPoor original installation with inadequate adhesive coverageIf the tile wasn't fully back-buttered during installation, voids behind it eventually show as hollow spots.
• PossibleMovement or flexing of the wall substrateNon-rigid backing (like plain drywall instead of cement board) can flex and break the tile bond over time.
• Less commonFreeze damage in unheated spacesIn unconditioned areas, trapped moisture that freezes can push tile away from the wall.

What to do

1. Tap several tiles with a coin or the handle of a screwdriver to map out how many sound hollow versus solid.
2. Inspect nearby grout and caulk lines closely for cracks or gaps that could be letting water in.
3. If only one or two tiles are affected and the area is small, they can potentially be removed, and reset with fresh thin-set adhesive.
4. Chip out the loose tile carefully with a chisel, trying not to damage the substrate or neighboring tiles.
5. Clean out old adhesive from the wall and the back of the tile if it's reusable.
6. Apply new thin-set adhesive and press the tile back into place, using spacers to match the surrounding grout lines.
7. Regrout around the reset tile once the adhesive cures, matching the existing grout color.

Tools and parts

• Small chisel
• Rubber mallet
• Notched trowel

When to call a pro

Call a tile contractor if multiple tiles sound hollow across a wide area, since this often means the substrate behind is damaged and needs a larger repair.

Safety