Tiles are loose or the wood finish is cloudy after a water leak

Tell a surface problem from a subfloor problem in five minutes

1. Find the water first. Look for the leaking supply line, the appliance, or the wall where rain gets in.
2. Walk the area barefoot. Soft, spongy or springy floor means the subfloor took the water.
3. Tap each tile with a coin. A hollow, empty sound means that tile has let go of the mortar.
4. Press on a loose tile and watch the grout line. Movement means the bond is gone, not the tile.
5. Lay a straight edge across the wood boards. Raised edges are cupping, and cupping is wet wood.
6. Look at the cloudy patch from a low angle. A white haze sitting in the finish is trapped moisture.
7. Tape the edge of the damage and check it in two weeks. Growing damage means water is still getting in.

If the floor is firm, the boards are flat, and the damage has stopped spreading, this is a covering job. Reset the tile or refinish the wood. If the floor moves, feels soft, or keeps growing, the subfloor is wet and a contractor has to open it.

Repair or replace

What it costs

Runhome contractor estimates for this job, including the trip and assessment. Loose tile work carries no range here, because none of the conversations behind this guide came with a tile estimate.

Can I do it myself?

Yes for a cloudy finish or a handful of loose tiles, as long as the floor under them is hard and dry. Resetting a tile is a scraper, a bag of thinset, and grout that matches. Hire a finisher for a whole room, because a rented drum sander leaves waves that only more sanding removes. Hire for the tile too when 35 to 40 tiles are loose, since that many means the substrate is the problem. If the floor flexes or feels soft underfoot, hire a contractor. That is the subfloor or a joist, and it is structural work.

What a contractor will ask you

Have these ready and you skip the back-and-forth.

• The size of the damaged area in feet, and the size of the whole room.
• A wide photo from a corner, showing the full floor, the damage, and the transitions to other rooms.
• How old the floor is, and whether it has been refinished before.
• What the damage looks like: cupped boards, dark stains, soft crumbly wood, or just a cloudy white finish.
• Whether the damage is one spot or spread across a large section.
• How many tiles are loose, and whether you have spare tiles from the original job.
• What is near the spot: a dishwasher, a sink, a bathroom, an exterior door, or a wall where rain comes in.
• Whether the damage has changed over the last few months or stayed the same.
• Whether furniture has to be moved, and what is in the room.
• Whether you want the damaged spot fixed or the whole room done.

Related questions

A water leak loosened about 35 to 40 tiles. Can they just be re-stuck?

Yes, when the floor under them is hard and dry. The old mortar has to come off the back of every tile and off the slab. Tiles pressed back onto old mortar come loose again.

The finish looks cloudy and white but the wood feels flat and solid. Is the floor ruined?

No. White haze is moisture caught in the finish, not damage in the wood. Sanding and refinishing removes it.

Do I have to replace the whole tile floor for a 3 by 4 foot spot?

No, not when the rest of the floor is sound. The water sets the size of the repair, not the room.

Should I fix the damaged spot or refinish the whole room?

Refinish the room when the spot sits out in the open. A spot repair matches color at best and never matches sheen.

How long after a leak do I wait before refinishing?

Wait until the wood stops changing, which is often 2 to 4 weeks with air moving over it. Finish over wet wood peels.