Most finish carpenters and homeowners are aware that seasonal changes in humidity and temperature cause windows, doors, trim, and flooring to shrink in the winter and expand in the summer but few realize how closely movement of woodwork is tied to moisture. Wood is a hydroscopic material, and will shrink or expand based on relative humidity; expanding when it takes on moisture, shrinking when it loses moisture. The chart below shows how drastically relative humidity can change the moisture content in wood.
In addition, did you know that if wet and dry pieces of wood are placed together in the same area, they will absorb or lose moisture until all pieces have the same final moisture content? This is called Equilibrium Moisture Content or EMC. The chart below shows the moisture content of wood based on relative humidity and temperature.
At any rate, wood moves and while you can’t stop it, you can avoid potential problems. Even the best of workmanship cannot prevent moisture-related defects and unfortunately, most moisture defects are irreversible. Moisture defects include surface checks, cracking, bowing, twisting, and warping.
So how can you avoid moisture problems in woodwork?
And for all you woodworkers, carpenters, and builders out there, here are some additional tips from the Architectural Woodworking Institute:
For in depth information regarding moisture and movement of woodwork, please use the links referenced (in blue) in this blog.
South Shore Millwork is proud to be an AWI Certified Quality Woodworker. Learn more at www.awiqcp.org
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