Repairing Water Damaged Wood Floors

wood floor with water damage
  • 1-40 hours
  • Intermediate
  • 0-4,000

Wood flooring has been a popular option for centuries, essentially starting with the first buildings in the western world. From those first log cabins, built exclusively out of materials found on the land, the personal connection with, and love for, wood products has never waned.

Wood floors are a long-lasting, durable selection for many household uses. They are a timeless example of interiors that bring elements of nature in.

Walk into any flooring department today and you’ll see endless options for wood flooring. From exotic hardwoods to the ubiquitous oak and maple, wood floors are still a top choice.

As popular as wood floors are, they’re not flawless. All flooring will show wear and wood floors are no different. The primary disadvantage of wood flooring is that it doesn’t respond well to moisture, spills, and floods.

If you have a piece of wood furniture with a water ring from a wet glass you’ll see what we’re talking about here.

Flooring takes a beating. Between shoes, animals, and standard household activities, it’s no surprise there are often spills and stains to deal with.

When it comes to wood flooring, there’s often more involved in cleanup than simply wiping up the mess. That’s because when wood gets wet, it swells. It also discolors. Neither is great for the look of wood flooring.

When the inevitable damage occurs, there are several ways to approach the situation, starting with the initial cleanup and perhaps progressing to a total floor refinish.

Signs of Water Damage

How do you even know if your wood floor is damaged? You may or may not have seen water on your floor. Perhaps someone else cleaned up a spill, or there was a leak beneath the washing machine or near the water heater you were unaware of.

Maybe water had a chance to evaporate before you saw a spill. Even if you didn’t see the original culprit, your wood floors will tell you the story.

Look for discoloration of the wood surface. This can be either a lighter or darker spot than the rest of the floor. Often it has kind of a marbled appearance, swirling together the colors of the wood with a white powdery look.

Water damage on wood floors can override the look of the floor’s finish, discoloring it to black, white, or darker/lighter shades of the wood color.

In addition to discoloration, the wood can warp in different ways. If you see a rippled effect across the surface of your floor, you’ve likely had some water damage. You may see a single board, or several planks that are dipped in the middle. If the edges are higher than the center, this is called cupping.

On the other hand, if the center is higher than the edges, it’s called crowning. When either occurs, the flooring can continue to warp until it cracks.

You may also see buckling, which is when the boards actually separate from the subfloor they were nailed to. This makes sense if the subfloor and top floor both suffered water damage, since the softer surface will release the nails holding planks in place.

Each of these types of damage require a slightly different repair approach.

warping wood floor

Types of Wood Flooring

Before we dig into the steps required to repair water damaged wood floors, it’s important to understand the type of flooring you’re working with.

The category of wood flooring has grown to encompass several types of flooring materials that are not 100% solid wood. This is important because your floor will react to water differently depending on the material and the installation technique that was used.

Original hardwood floors are solid wood that is cut into planks and nailed into place during installation. It may or may not come prefinished when you buy it. If it doesn't already have a finish on it, it will need one after installation.

Engineered hardwoods still fall into the hardwood category. They are still wood, but the composition is different from solid hardwood. Instead of a solid piece of wood, engineered products are made up of layers of pressed wood.

Because of the process involved, engineered hardwoods are typically more water resistant than solid hardwoods. However, if water breaks through the surface, settling into the cracks of the engineered product, it can still cause warping and buckling.

Engineered hardwoods come in a vast array of qualities and styles, some of which are nailed down, some are glued, and others are installed as a floating floor, much like other click-together laminates.

The type of installation can affect your repair efforts since a floating board is easier to remove if necessary.

There are also other material combinations that may fall into the wood floor category. For example, there’s a product line of flooring that has tile at its base with a layer of hardwood on the surface.

These products are highly water resistant because the tile isn’t a porous material. However, it doesn’t mean they can’t suffer damage, especially on the surface layer.

wood floor with water damage

Basic Cleanup

If you see any type of liquid on your wood floor, you need to address it as quickly as possible. Start by wiping up the liquid. If the area was flooded by a bathtub, leaking sink, washing machine, dishwasher, water heater, or other source, suck up the water with the help of a wet/dry vac.

Whether you got to it right away or you found the damage later, the next step is to clean the area. The type of spill might be a factor here. For greywater, you can clean and sanitize the space fairly easily. The same goes for a spilled glass of water, exposure from an open window, or a drip from the ceiling.

If it’s a black water or chemical spill, call in professionals to complete the cleanup. In this case, it’s essential the right cleaners are used in order to avoid future mold growth and other toxic issues.

Even straight water can lead to mildew so the disinfecting step is important regardless of what caused the damage.

Remove Moisture From the Area

Once you’ve mopped up the mess and cleaned the space, it’s time for a thorough dry. Open the windows if it’s warm enough. Turn up the heat in the house if it’s not.

Avoid putting heat directly on the wet boards, since it can quickly cause over drying, which leads to cracking. For this reason, you can use a space heater to warm the air, but don’t direct it to the floor.

Set up a humidifier and allow it to run for a minimum of 12 to 24 hours. You should see the collection slow considerably over time.

Treat Mold

If you came into the situation after mold began developing, address it as soon as possible. Mold on the surface is easier to address than mold that forms beneath the boards.

Start with a mild cleaner like dish soap and water if there is a small patch of mold on the surface of a board. For more invasive mold, use a mold and mildew cleaner, TSP, or a bleach solution. Be sure to wear safety gear, including gloves, a mask, and goggles.

If the mold is growing beneath the boards, they will have to be removed and treated by cleaning or sanding down the surface so it can be refinished.

Surface Stains

If cleaning the area doesn’t remove the stain, you’ll need to sand it down. Start with a rough sandpaper, such as a 50 or 60 grit. Move through different grits until you reach a very fine sandpaper that creates a soft finish.

Fix Cupping and Crowning

If mold isn’t the issue, but the boards are suffering from cupping or crowning, you’ll need to get out the power sander. For minor issues, a sanding block will do.

When sanding, work with the grain of the wood. While you want to make sure to create a level floor, try not to sand a larger area than is necessary for the repair.

Address Buckling

If the boards have warped to the point that they’ve separated from the surrounding flooring or the subfloor, you’ll need to remove the affected boards. For minor buckling you may be able to nail down the affected edge. However, if the board will no longer sit flush, even if you sand it down, it will need to be replaced.

wood floor with major water damage

Replace Boards

If it comes down to replacing boards, you’ll need to figure out how the original materials were installed. For some applications, you’ll need to use a reciprocating saw to cut out the old board. Then you can glue or nail a new board into place.

Boards that were nailed into place can be gently pried away from the floor. You may need to remove the section all the way to the nearest wall so you can repeat the tongue in groove pattern during installation.

As a shortcut, you can shave off the ‘tongue’ side of a new board on both the end and one side. Then slide the grooved sides into place and glue or nail it down.

This isn’t the best option for high traffic areas since the board may still shift. However, it’s an easy fix for a spot that doesn’t see much traffic.

Apply Finish

Regardless of whether you sanded down a small spot on a board or replaced a corner of the room, you’ll need to put a protective coat on the top of the wood. With any luck, you’ll already have some of the original wood finish in the garage somewhere. If not, take a sample piece to your local paint shop and ask for a match.

Apply the finish as per the directions and allow it to dry thoroughly.

Refinish floors

If a large area of wood flooring suffered damage, it might require you to refinish the entire floor.

As with the other techniques, make sure you’ve removed all moisture, mold, and bacteria before resealing floors.

If your floors are solid hardwood, this is a standard procedure. However, if you have engineered hardwood or a mixed material, your ability to refinish the floor depends on the depth of the top layer of wood.

Higher quality engineered hardwoods can be refinished a time or two before they wear too thin. Lower quality flooring will need to be replaced instead.

Although it’s a straightforward process, refinishing wood floors is a skilled craft. Like most similar jobs, getting the finished look you want starts with fantastic prep work.

In addition to replacing warped boards, ensuring the stability of the floor, and filling any gaps or cracks, you’ll need to be meticulous in your sanding process. Every misstep will show up once you put the finish on. If you’re not confident in your skills, hire a professional for the sanding and refinishing.

Preventing Water Damage on Wood Floors

Accidents happen and you can’t always prevent them. But there are some everyday practices that will reduce risk. For example, make sure you have a pan beneath your water heater. Regularly check beneath the washing machine and dishwasher by adding it to your maintenance schedule.

Always place plants on a tray or a saucer to catch drainage.

Also, use water-resistant rugs in areas where water is prevalent, such as kitchens, bathrooms, laundry rooms, and mud rooms. All-natural materials like cotton also work well since they are easy to remove and dry out.

If you have the option, don’t install solid hardwood in water-prone areas.

If you’re leaving town, turn off your home’s water at the source. Another option is to turn off faucets beneath each sink. This not only helps prevent water leaks but will minimize the chance of returning home to a well-damaged floor that has been sitting unattended.

If you do encounter water damage for any reason, from a leaking roof to a dripping plant, be sure to contact your homeowner’s insurance company to evaluate coverage for the damage. Also, take pictures and keep a record of the damage.

Dig deeper on the topic with our articles Invisible Causes of Water Damage and How to Smell Water Damage.