Saving Wet Hardwood, Engineered, Laminate and Vinyl Plank Floors

Know Which Floor You Have

Wood look floors come in four main types, and water treats each one differently. Pull a floor vent cover or a threshold strip to see the edge of a board if you are not sure.

Also find out what is under the floor. Wood over a plywood subfloor with a crawlspace or basement below can dry from both sides. Wood glued or floated over a concrete slab dries only from the top and takes longer.

The First Hours on Any Floor

Speed matters most with wood. Every hour water sits on the surface, more soaks into the seams and the edges of the boards.

• Stop the source and make the area electrically safe.
• Pull standing water with a squeegee and a wet/dry vacuum, working along the length of the boards.
• Get area rugs off the floor. A wet rug holds water against the wood and can bleed dye.
• Move furniture out, since the floor under it cannot dry.
• Remove baseboards and quarter round along wet walls so air can reach the edges of the floor and the wall.
• Close the room and start a dehumidifier. Point fans across the floor surface, not straight down at it.

Do not use a steam mop, a heat gun or a space heater aimed at the floor. Fast, uneven drying can crack and split boards, and aggressive heat on the surface while the bottom stays wet makes cupping worse.

Keep the room around 70 to 80°F and aim for indoor humidity under 50%, lower if you can.

Cupping, Crowning and Buckling Explained

Wood swells as it takes on water and shrinks as it dries. Where the water is decides the shape the floor takes.

• Cupping means the edges of each board are higher than the center. The bottom of the board is wetter than the top. This is the most common shape after a leak and often improves as the floor dries.
• Crowning means the center is higher than the edges. It happens when a cupped floor is sanded flat before it dries. Once the bottom dries and shrinks, the sanded edges end up low.
• Buckling means boards have lifted right off the subfloor, sometimes by several inches. The swelling had nowhere to go. Buckled boards usually need to be removed.

Small gaps may open between boards as the floor dries. That is normal and often closes again as the house returns to its usual humidity.

Watch for signs that are not about shape. Dark gray or black stains around nail holes and seams mean water reacted with the wood and may not sand out. Soft spots, a bouncy feel or a musty smell point to trouble below the floor.

Measuring Moisture in a Wood Floor

You cannot judge a wood floor by touch. A pin moisture meter with a wood setting is the right tool.

1. Set the meter to the right wood species if it has that option. Oak is the most common.
2. Take readings in an unaffected room with the same flooring. This is your dry standard. In a dry climate it may be as low as 6% to 8%. In a humid one it may be higher.
3. In the wet area, take readings on a grid every 2 feet. Mark each spot with painter’s tape and write the number and date on it.
4. Check the subfloor too, from a basement or crawlspace below if you can, or through a floor vent opening.
5. Take readings at the same spots once a day.

The goal is for the wet area to read close to your dry standard, within about a point or two, and to stay there for several days. Readings in the high teens and up mean the wood is still wet.

The top of the board dries first. A board can read fine at the surface and still be wet at the bottom, which is why pros often drive pins deeper or take readings from underneath.

Drying Solid and Engineered Wood

For a small wet area caught early, home equipment can do the job. Run a dehumidifier in the closed room, keep fans moving air across the surface, and check readings daily. A few boards along a kitchen sink or dishwasher often dry in 5 to 10 days.

For a floor that is wet across a room, professionals use floor drying mats. These are panels sealed to the floor that pull air down through the seams and draw moisture out of the wood and subfloor from above. Paired with a dehumidifier in a tented or closed space, they can save floors that would otherwise be torn out. Drying time is often 1 to 3 weeks.

Dry from below if you can. In a crawlspace or basement, point a fan at the underside of the subfloor and run a dehumidifier there too. Remove any wet insulation between the joists.

Engineered wood needs a close eye. If the top wood layer starts to peel, bubble or separate from the core, those boards will need to be replaced even after they dry.

Do not rush it. Wood that is dried too fast can crack and check, and wood that is not dried fully will move again later.

Laminate and Vinyl Plank

Laminate has a fiberboard core. When water reaches the core, usually through the seams, the edges swell and lift. That swelling almost never goes back down. Swollen laminate boards are replaced, not dried.

The bigger concern with laminate is what is under it. Laminate floats on a thin foam underlayment, often with a plastic sheet, and water gets trapped there. Most laminate clicks together, so you can remove it starting at the wall nearest the water. Stack unswollen boards flat to dry, dry the subfloor fully, then reinstall them with new underlayment. Having a few spare boxes of the same product makes this far easier.

Vinyl plank resists water itself, but water runs through the seams and sits under it with nowhere to go. If the planks click together, lift them in the wet area, dry the subfloor, clean the back of each plank, and click them back in. Glue down vinyl is harder to lift and may need a flooring pro.

If water sat under laminate or vinyl for days and you smell something musty when you lift a board, look for mold on the subfloor and the underlayment. Clean or replace as needed before you reinstall anything.

Wait Before Sanding, and When to Replace

The biggest mistake with wet hardwood is refinishing too soon. Wait until readings in the wet area match your dry standard and stay there, then give the floor more time to settle. Many flooring pros wait several weeks to a couple of months after a leak. A cupped floor often flattens on its own as it dries, and any cupping that is left can then be sanded out without leaving the floor crowned.

Replace boards or the whole floor when any of these are true.

• The water was sewage or outdoor flood water.
• Boards have buckled off the subfloor.
• Laminate edges have swollen.
• Engineered boards have delaminated.
• The floor is still cupped after drying and the wood is too thin to sand.
• Deep black stains remain around seams and nails.
• Mold is growing on the underside or the subfloor.

Replacing part of a hardwood floor and blending it in is skilled work. A good flooring contractor can weave new boards into the old ones and refinish the room so the repair does not show.

Step by Step

1. Identify the Floor

   Check a board edge at a vent or threshold to see if it is solid wood, engineered, laminate or vinyl. Note whether a slab or a wood subfloor is underneath.

2. Remove Surface Water

   Squeegee and vacuum water off the floor right away, working along the boards. Move rugs and furniture out.

3. Pull Baseboards

   Pry off baseboards and quarter round along wet walls and number them so they go back in place.

4. Take a Dry Standard

   Read the same flooring in a room that stayed dry. Write the number down as your target.

5. Grid and Log Readings

   Take readings every 2 feet in the wet area, mark each spot with tape and log the number and date.

6. Set Up Gentle Drying

   Run a dehumidifier in the closed room and fans across the surface. Dry the subfloor from below if there is a crawlspace or basement.

7. Lift Laminate or Vinyl Plank

   For click floors, remove planks in the wet area, dry the subfloor fully and set unswollen planks aside to reinstall.

8. Watch Daily

   Check readings and the floor’s shape each day. Call a pro if readings are not dropping after 3 or 4 days.

9. Wait Before Refinishing

   Only sand or refinish when readings match the dry standard and have held there, often several weeks after the leak.

Mistakes That Make It Worse

• Sanding a cupped floor flat too soon. When the wood finishes drying it crowns and the floor is ruined.
• Heating the floor surface hard to speed drying. The top shrinks while the bottom stays wet and boards crack.
• Leaving a wet rug or furniture on the wood. The floor under them stays wet and stains.
• Drying laminate in place and hoping the edges settle. Swollen fiberboard does not shrink back.
• Ignoring the subfloor. A dry looking floor over a wet subfloor will cup again and can grow mold.

Where You Live Matters