What should I do when water gets under tile?
Stop the water and dry the surface, then have the floor checked with a moisture meter. The EPA's guidance for ceramic tile, linoleum and vinyl is to vacuum or wipe the surface, then check that the underflooring is dry and dry it if needed (EPA).
Does it matter if the tile is on a slab or a wood subfloor?
Yes. The LSU AgCenter says ceramic tile, stone and solid vinyl on a concrete slab may be cleaned in place (LSU AgCenter). Tile over a wood subfloor is different: wood can swell, buckle or delaminate, and the flooring may have to come up so the subfloor can dry or be replaced.
How can I tell water is still under the tile?
Dark grout that stays dark after the surface dries, loose or hollow-sounding tiles, cracked grout and a musty smell are common signs. A moisture meter reading compared with a dry room is the way to know.
Does the type of water change the cleanup?
Yes. Clean water can usually be dried. Contaminated water needs cleaning and disinfecting, and porous materials it soaked are often removed.
Water from a clean supply line is Category 1. Washing machine and dishwasher overflows are Category 2, and sewage, toilet backflow with feces and surface water flowing into a building are Category 3 (Massachusetts DPH).
Common questions
Can tile be dried without pulling it up?
Often, if it is on a slab and the water was clean. Tile over a wood subfloor may need some tiles removed to dry the wood underneath.
Why is my grout still dark days later?
Grout and the thinset underneath can hold moisture. Dark grout that will not lighten can mean water is still underneath.
Is sheet vinyl the same as tile?
No. The LSU AgCenter says paper-backed sheet vinyl can hold moisture and may need to be replaced if it discolors or loosens.
Related guides
Sources
- EPA: Mold Remediation in Schools and Commercial Buildings, Table 1
- LSU AgCenter: safe removal and cleaning of floors after a flood
- Massachusetts DPH: quick reference, water damage response in buildings
- EPA: A Brief Guide to Mold, Moisture and Your Home
Last reviewed November 13, 2026. This guide is general information, not legal, insurance or medical advice.