The short answer
Why Tile Traps Water
Tile and grout are waterproof on the surface, but water can seep through cracks, loose grout, or along edges. Once moisture gets under the tile, it sits against the subfloor with no way to escape. The tile acts like a lid, holding dampness against the wood or concrete below.
That trapped moisture softens wood subfloors, weakens adhesive, and encourages mold growth. You may notice a musty smell, discolored grout, or a spongy feel when you walk. The longer the water stays, the more damage it does, so quick action matters.
Steps to Start Drying
First, remove the tile and grout in the affected area. You can use a chisel and hammer, or a floor scraper, but work carefully to avoid damaging the subfloor underneath. If the tile is cracked or loose, it may come up easily. If not, you might need to break it into pieces.
Once the tile is up, sweep away debris and check the subfloor for soft spots or dark stains. Use a wet vacuum to pull up standing water, then set up fans and a dehumidifier. Open windows if the weather is dry, but in humid conditions, keep them closed and rely on dehumidifiers.
Keep the air moving for several days. The subfloor must feel dry to the touch and show no moisture meter readings above normal before you consider reinstalling tile. In humid climates, this process can take longer.
- Remove all tile and grout in the wet area
- Use a wet vacuum to extract standing water
- Set up high-velocity fans and a dehumidifier
- Check for soft spots or mold growth
- Let the subfloor dry for several days
- Test moisture levels before replacing tile
When to Call the Pros
If the water came from a sewage backup, a flood, or a leak that soaked the subfloor for days, call local water damage pros. They have industrial drying equipment and moisture meters that show exactly where water hides. They can also remove and replace subfloor sections that are too damaged to save.
The pros can also inspect behind walls and under cabinets, where water often travels unseen. If you see mold or smell a strong musty odor, a mold professional may be needed. Acting quickly helps prevent more costly repairs later.
Dealing with Damaged Subfloor
If the subfloor is plywood or OSB, it might swell, warp, or delaminate after getting wet. Press on it with your thumb; if it feels soft or crumbles, it needs replacement. For concrete subfloors, the surface may need grinding to remove adhesive residue and ensure a flat base for new tile.
Replacing a section of subfloor involves cutting out the damaged piece and screwing in new plywood that matches the thickness. This is a job many homeowners can do, but it requires care to keep the floor level. If you are unsure, local water damage pros can handle the removal and replacement.
Preventing Future Water Damage
Check your tile and grout regularly for cracks or gaps. Reapply grout sealer every year or two to keep water from seeping through. Fix plumbing leaks promptly, and know where your main water shutoff valve is so you can stop a burst pipe quickly.
In humid climates, keep indoor humidity low with air conditioning or a dehumidifier, especially after heavy rains. If you have a leak, act within 24 to 48 hours to minimize subfloor damage. Consider installing a leak detector near water heaters and washing machines.
Need help right now?
Water keeps spreading into floors and walls, so it is worth acting early. Calls are answered 24/7.
Call Now (386) 272-5697Frequently asked questions
Can I dry a wet subfloor without removing the tile?
No, not effectively. Tile and grout create a barrier that prevents moisture from evaporating. You must remove the tile to let air reach the subfloor. Drilling small holes is rarely enough and can damage the tile further.
How long does it take for a subfloor to dry?
It typically takes 3 to 7 days with fans and dehumidifiers, but the exact time depends on how much water soaked in, the type of subfloor, and humidity levels. Use a moisture meter to know when it is dry.
What if the subfloor is already moldy?
If you see mold growth or smell a musty odor, stop drying and call a mold professional. Mold can spread quickly and pose health risks. The pros can remove affected subfloor sections and treat the area safely.