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Frequently Asked Questions


The damaging effect of water on wood builds over time.  By the time you notice a change in your wood floor, the water has already hurt the floor.  One of the first signs that water has damaged your floor is cupping of individual planks, or crowning of several planks, creating a hump in the floor.  As the photos below suggest, once the wood absorbs water, it expands and this expansion reveals itself in the edges of the board turning up, or whole planks buckling.

Another sign that water has damaged your floor is black or dark staining along the edges of a plank or broader stains across several planks. This staining is most often caused by a combination of mold growing, the tannins in the wood turning color as they react to prolonged contact with minerals in the water, and occasionally rust appearing along the edges of the board where nails exist. In each of these instances, a consistent source of water is required to cause the damage.


Before you try to repair the damage, the first question to ask is, “where did the water come from?”  An occasional spill won’t cause mold to form or the tannins in the wood to turn color or even create a cupped appearance.  Persistent moisture overtime is required for these problems to manifest themselves. External sources of water are often the first place homeowners look. If you’re noticing staining by windows or doors there, it’s likely that water is seeping underneath the door sill or down the framing on a poorly installed or older window. Often, especially around windows, you’ll notice signs of water on the drywall in the form of peeling paint or staining.

More commonly, we’ll find water damage on wood flooring that was caused by internal sources of water.

If you’ve got hot water heater in your home with radiators installed in each room, you should investigate whether one of the connections to the radiator is leaking. Because the connectors and valves are above the floor, you’ll be able to do a visual inspection to identify leaks.

More difficult to identify are internal sources of water that are hidden behind walls, cabinets, or underneath appliances.

Recently, we’re seeing more and more water damage from refrigerators and dishwashers.  A number of refrigerators have water filters located beneath or behind the fridge.  Occasionally these filters will clog, or the filter housings/lines crack creating a small, persistent drip of water.  These drips, over time, work their way down between the boards and behind the appliance, spoiling the floor and causing damaged planks in front of the appliance.

Another increasingly common source of leaks in the kitchen is from the drain hoses of dishwashers.  For some reason, the plastic, flexible drain hoses are so cheaply made that within a few years, cracks can form that drip water down to the floor.  Center islands, where the subfloor is often exposed to provide access for plumbing and electricity, are especially vulnerable to this problem.  Water that drips from the dishwasher hits the subfloor and can travel for several feet.  If there’s enough water, it can be absorbed by the hardwood flooring above, causing staining, cupping, or crowning.

Another common problem with dishwasher drain hoses is that they are not supported properly.  Because the plastic hoses must make a bend or two, and are often longer than required, tight bends will crack over time, creating a hidden leak that can ruin your wood floor.

No matter what the source of the water, the leak must be found and fixed before repairs to the flooring can be made.


Water-damaged boards that suffer from mild cupping or simple surface staining can be sanded down in the field, re-stained and re-coated. While this may sound like a reasonably simple task, it really isn’t for a couple of reasons. First, wood flooring changes color over time as sunlight darkens or lightens the wood, depending on the species.  When you sand a floor, the original color of the wood is often revealed and even when the exact same stain is applied, can appear a slightly different color.

It’s also difficult to completely hide the lap and cut lines made when new finish is applied over a repaired area.  While most polyurethane coatings are self-leveling when applied, it’s inevitable that where the original and repaired flooring meet, there will be small but noticeable differences in the “strokes” used to apply the coating.  This is why in many cases even a small area of repair and sanding requires that the floors in the entire room are refinished to blend in the colors.

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