Real Estate News

When to be concerned about the gaps in your hardwood floor

Contractor Rob Robillard discusses expansion and contraction and how humidity can affect the wood in your home.

Many times, a seasonal gap, one in which you can fit a dime, will close back up in higher humidity. Rob Robillard

Q. I have 2-inch-wide red oak flooring throughout my house, which was built in 1984. In many areas, there are gaps from 1/32 to 1/16th of an inch between the boards. Is there a filler I can use? I am assuming the floors will have to be refinished after the filler is applied and has dried.


A. Did you notice these gaps during the summer? Gaps in wood floors are normal and occur when the wood loses its moisture content. Several factors can be the cause.

Often gapping can result with flooring installed during periods of higher humidity. Months later, usually during the heating season, those gaps start to show up. The good news is that they usually close back up. Many times, a seasonal gap, one in which you can fit a dime, will close back up in higher humidity.


Indoor humidity imbalance can also cause gapping. The ideal humidity level is 30 percent to 50 percent, and the ideal temperature range is 60 to 80 degrees. All the wood in your home will expand or contract as moisture in the air changes. You may also notice that your doors or wood windows will swell and stick during rainy seasons.

Large gaps in wood floors that do not close up during the summer months could be a result of excessive moisture (check the crawl space below), being located too close to a heating vent, incorrect nail spacing, or structural settlement issues.

For normal gaps, no repairs are needed. Adding filler is not a good idea; it will get pushed out as the wood expands with moisture.

For larger gaps that don’t close up, call in a professional contractor who can repair floors properly. The best times to repair hardwood floors are April and October.

Q. I replaced my windows about 10 years ago with double-paned ones. I live by the ocean, so we get a lot of horizontal rain, and some windows facing the water now have constant condensation between the glass. What can I do to get rid of this?



A. I’m not convinced that this has anything to do with horizontal rain or coastal air. Double-pane windows have a layer of gas (usually argon or krypton) trapped between two panes of glass that acts as insulation to reduce heat loss through the window. If multiple-pane windows have condensation, it means that the seal protecting the window assembly has probably failed. Check with your manufacturer to see whether the windows are still under warranty.

Rob Robillard is a general contractor, carpenter, editor of, and principal of a carpentry and renovation business. Send your questions to [email protected] or tweet them to @robertrobillard.


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