Q. My 7-year-old hardwood floor needs to be refinished because the stain faded from the sun. I was hoping to restain it with a product that could withstand direct sunlight. Do you have any recommendations?
A. Michael Purser, a second-generation wood-flooring contractor in Atlanta, responds: While it's true that floor finishes with UV inhibitors and stains with pigments (as opposed to dyes) will slow down color degradation in both the finish itself and the underlying wood, manufacturers of these products don't claim to be able to stop the problem. And UV light (from the sun and from other sources) isn't the only cause of fading and discoloration; heat and moisture can also be factors. To slow down — notice I didn't say "prevent" — fading and deterioration, you'll have to manage all three causes. The key is to avoid extremes of exposure to sunlight and humidity.
If you are building a new house or adding on and have any input in the selection of new windows, you would be wise to consider low-E glass. Made of transparent metallic oxides, low-E coatings can reflect up to 90 percent of long-wave IR light, the kind that creates the heat that accelerates oxidation in wood. But low-E glass doesn't stop a lot of UV light, the most damaging type. For that, you'll need to choose windows that feature glass with a UV-blocking coating. If you have to work with older existing windows, you might want to investigate window films. Often applied to the interior glass of historic properties — where protecting wood floors, old rugs, and expensive fabrics is a high priority — these thin, multilayered film products have various coatings that can selectively reduce UV, IR, and visible light, all of which contribute to fading.
Finally, there's a low-tech solution: window coverings. Drapes, shutters, and blinds may not be what you had in mind when you bought or built your home, but this is an approach previous generations put to good use. Compared with refinishing your floor or retrofitting new windows, window coverings are also fairly cheap. The bottom line is that sunlight is very destructive to wood, as well as to the various finishes used to protect it; you can slow fading down, but you can't stop it. So your focus should be on the light entering the room and how to reduce its intensity.
