Water Damaged floor repairs, what you need to know…

Hardwood flooring repairs to water damaged boards are not quite as simple is many people think. When a refrigerator or dishwasher leaks onto a wood floor logic would make you think that once it is dry, the coast is clear. The problem is that often the flooring can deform from excessive moisture levels. Sure it can be sanded flat, but that only fixes the issues that are visible.

What happens that can be concerning for water leaks is that the fasteners can become loose or rust. As the expanding wood fibers push against the fastener, they compress. After the flooring has dried completely, the fibers retract. This leaves a void around the fastener and can allow movement of the boards.

Compression set or “edge crush” is another complication of wet flooring. As the flooring is expanding after the leak, the edges crush wood fibers on the board seams once enough resistance is encountered. After the sides of the boards compress inward as much as the can, they push upward. After the flooring reaches proper moisture content, the boards typically end up with gaps that can be as wide as 3/16″. You can fill a gap this large, but the solution is temporary. The wood filler can crack and pop out of the wood floor as it expands and contracts at a different rate then the flooring. Combine this with loose fasteners and the result can be a recipe for disaster.

When a floor experiences a leak, it can come from a variety of sources. The key issue is that it takes time for the boards to dry. Depending on the moisture increase following a leak, it can take one to two months for the drying process. If you are talking with contractors about a repair, you must consider that sanding a floor too soon is bad news. If you sand a hardwood floor that has not dried following a leak, then you often create crowning.

The next hidden problem

Crowned wood floors are an even worse situation in many ways. In a climate like central Oregon and Bend, crowning can be extreme if a floor is sanded too soon. This is because the equilibrium moisture content of flooring for the region is close to 6 percent. If you have a leak that raises the EMC to 12% or greater, then the dimensional change afterwards can be profound. Most leaks that raise the edges of wood flooring happen above 12% moisture content.

And the problem gets worse…

Sanding a crowned floor can remove 1/8″ of wear layer or more from the surface of flooring. This can result in a wood floor with very little life remaining for additional service. A typical solid wood floor has a wear layer thickness of 5/16″. After water damage a few poorly planned repairs, you may end up with an unserviceable floor.

So what should you do if you have a leak?

Aside from finding the source of the leak, my advice is to relax. By the time you see flooring that is cupped, it is often too late for a quick fix. The key is how you plan the repair. There are two options that work well:

  1. Remove the affected flooring and replace with matching flooring. Afterwards, to a get a proper appearance you will likely need to refinish the entire wood floor. Sunlight and normal foot traffic can affect the color and sheen of the original finish. If you try to fix only a small section without an entire refinish the repair is usually very obvious. It can be possible today blend the appearance, but I have known very few people who do this extremely well.
  2. Wait and monitor. It is likely that your floor is okay, but you really need someone with experience to evaluate it. The board moisture content will need to be measured with a calibrated moisture meter. Once you have a baseline reading, you can then approximate the timeline. Having a fan in the room can help evacuate some of the moisture, but does very little in many cases.

My goal is to provide you only with a picture of the reality of how to plan for repairs following a water leak. If there was an area in which mistakes are made, this is a big one.

Thanks for reading and let us know if you have any questions.





Leave a Comment