Tile and grout are not the waterproofing system in a shower. They are the finish. A reliable shower requires a water-management assembly behind or directly beneath the tile that connects the walls, floor, drain, curb, corners and penetrations without leaving unintended paths for water.
Why Good-Looking Tile Can Still Leak
Schluter explicitly states that tile coverings are not inherently waterproof. Water can move through grout joints and into the assembly. That is why tiled showers use either traditional water-management methods or bonded waterproofing systems designed to route water to the drain and protect moisture-sensitive materials.
The Important Parts Are Mostly Hidden
- Shower base: must direct water toward the drain rather than creating a saturated flat basin.
- Waterproof layer: liner, sheet membrane, liquid-applied membrane or another approved system.
- Drain connection: the waterproofing has to integrate with the drain method being used.
- Corners and changes of plane: need continuous treatment appropriate to the system.
- Pipe/valve penetrations: cannot simply be holes cut through an otherwise waterproof layer without the specified sealing detail.
- Curb/threshold: penetrations and transitions are frequent failure points.
Backer Board Is Not Automatically the Waterproofing
Some backer boards tolerate water exposure but are not themselves a complete waterproof shower assembly. The entire selected method—including seams, fasteners, transitions and drain—must be installed as a compatible system.
Sealing the Grout Does Not Repair a Bad Shower Pan
Grout sealer can reduce staining or water absorption in some cementitious grout. It does not substitute for a failed pan liner, membrane, drain connection or waterproofing detail. If a shower leaks into adjoining rooms or below the floor, surface sealing should not be the first diagnosis.
Florida Permit/Trade Boundary
Ordinary tile work and shower-system reconstruction are not always the same regulatory scope. Replacing a shower pan, moving plumbing or changing other building systems can trigger permits or licensed-trade requirements even when simple tile replacement would not. Check the actual scope with the local building department.