How to Save a Water-Damaged Wood Floor

How to Remove Water From Wood Floors

The sooner you can attend to your wet floors, the better. Wood's cellulose fibers rapidly soak up water but release that water more slowly. Therefore, you should start pulling off the water with your shop vacuum as soon as possible. Even if you believe your wood floors are so well-finished that water cannot penetrate to the raw wood, think again. Wood floors have many infiltration points besides the top layer: between seams, through breaks in the coating, under baseboards, through heating registers, and a host of other areas.

The secret to preventing mold and mildew growth is the same as with carpeting: Eliminate the dirt. It's not just water that causes mold and mildew; it's the combination of water and dirt.

1. Remove Surface Water

   Use a shop vacuum on "wet mode" (no bag) to remove as much water as possible from the surface of the flooring. This is easiest with a wide flooring attachment on the vacuum hose. It also helps to use a squeegee to gather the water as you suck it up.

2. Scrub the Floor

   Mix a mild detergent and a compatible disinfectant (such as Mr. Clean) with clean water in a bucket. Scrub the entire floor and all related woodwork (baseboards, stairs and newel posts, etc.) with a stiff brush, rinsing the brush frequently in the bucket. Do not pour the water onto the floor (there's no reason to add more water to the problem). Scrub thoroughly to remove all dirt, mud, silt, and organic material, all of which can promote mold growth.

3. Treat Moldy Areas

   Clean areas that show signs of mold with TSP (trisodium phosphate) or TSP substitute mixed with water. Scrub affected areas with the solution until the mold and mold discoloration are gone, then rinse with clear water, and dry the surface with an absorbent cloth.

4. Dry the Floor

   Dry the floor naturally and slowly with fans and plenty of airflow through the space. Open windows and doors (unless the outdoor air is more humid than the indoor air), and run fans to move air through the space. For example, place a box fan in a large window or door opening so the fan blows out, then open windows and/or doors on the opposite side of the space to allow fresh air in. This provides cross-ventilation to move the moisture out.

   Warning

   It is important to dry the floor steadily but slowly. Wood flooring dried too quickly can crack. Do not apply heat to the hardwood flooring, as this can result in splitting, cupping, and other problems.

5. Sand Water-Damaged Wood Flooring

   After drying a wood floor, you may have some concave or convex floorboards; this is called "cupping." Heavy sanding with a drum or orbital sander can actually "take down" some minor high areas. However, heavily cupped wood cannot be sanded down flat. It is inevitable that some floorboards may lift up completely at the ends. In this case, face-nail the floorboards back down.

   Tip

   Cupping can also be a sign that the wood is not completely dry on the opposite side, even if the surface is dry. If the other side is still damp or wet, it causes more expansion on the bottom than on the surface. Make sure all of the wood—top and bottom surfaces—is as dry as possible before sanding.

6. Deal With Mold on Wood Under Paint

   Mold growth under paint on a painted floor is a trickier issue. Your only recourse at this point is to remove the finish because paint creates a seal over the floor that traps water in the wood below. After scraping off the paint, scrub the wood with an abrasive cleaner, such as Barkeeper's Friend, or use a TSP-water solution with an added cup of ordinary laundry bleach per gallon of water. Dry the floor as described above after cleaning.

7. Replace Laminate

   Laminate flooring can have a similar appearance to solid hardwood or engineered hardwood, but it is not the same material. The majority of a laminate flooring plank is made with wood pulp, much like particleboard or MDF (medium-density fiberboard). This material is highly vulnerable to water damage and swells when it gets soaked, ruining the integrity of the material. Most laminate flooring that is water-damaged must be replaced.