Acclimation is a critical step in wood flooring installation that contributes to its long-term stability and performance. Acclimation is the process that allows wood products to adjust to the temperature and relative humidity of the environment before being installed. When performed properly, acclimation helps mitigate expansion, contraction, warping and other moisture-related issues that can compromise the integrity of the floor and lead to callbacks.
To master moisture concerns and set up every job for success, wood flooring professionals routinely apply the tools and data provided by the United States Department of Agriculture (USDA) Forest Products Laboratory and the National Wood Flooring Association (NWFA) and follow the best practices established by the industry.
Chief among them:
Calculating moisture content. Since wood is a hygroscopic material that absorbs and releases moisture in response to environmental conditions, one important tool for assessing the moisture content (MC) of wood flooring products is the USDA Forest Products Laboratory’s Wood Handbook: Wood As an Engineering Material. This publication includes regional MC data for wood used in interior applications. While these measures are helpful, indoor conditions vary and require additional tools for assessment like the NWFA’s Equilibrium Moisture Content (EMC) tables. EMC tables are the standard for wood flooring professionals to calculate the appropriate MC of wood flooring.
Expert tips for acclimation and installation. In order to achieve optimal moisture conditions and stable, long-lasting wood floor performance, flooring experts at the International Standards & Training Alliance (INSTALL) recommend following these steps:
- Prepare the jobsite. Before delivery, measure and record the temperature, relative humidity and subfloor moisture content. Make sure the environment meets the manufacturer’s recommended conditions for both the wood flooring and subfloor.
- Verify conditions at delivery. Upon flooring delivery, recheck and document jobsite conditions to confirm they remain within acceptable ranges.
- Moisture test. Use a moisture meter set for the correct wood species. Pay close attention to areas prone to moisture. Compare readings to NWFA EMC tables and manufacturer specifications to confirm compatibility.
- Address moisture issues. If high moisture levels are detected, delay installation and resolve the issue before proceeding.
- Install when conditions are stable. When all measurements confirm the flooring and environment are within the acceptable range, installation can proceed.
- Allow for post-installation conditioning. After installation, allow unfinished wood flooring to stabilize for five to seven days before sanding and finishing.
Taking the time to test installation conditions, resolve moisture issues and follow established standards and manufacturer guidelines helps ensure a smooth, successful installation—and a satisfied customer.
David Gross is the executive director of INSTALL, the leading organization for floorcovering installation training and certification in North America at INSTALLFloors.org. He holds a bachelor’s degree in economics, an MBA and is a BCSP Certified Safety Professional with more than 30 years of hands-on floor installation experience.
