Acclimating Hardwood Floors

National Wood Flooring Association (NWFA) defines acclimation as the process of adjusting the moisture content of wood flooring to the environment in which it is expected to perform.

When floors are not properly acclimated, they may expand or shrink after installation, resulting in cupping, crowning or squeaking.

There are no hard estimates for how long it will take wood to acclimate, but allow for anywhere between 5 and 14 days. The time will depend on many factors, including:

The goal of acclimation is to reach equilibrium moisture content (EMC) in the flooring, a point at which the wood will neither lose nor gain moisture. The chart showing proper moisture content for wood flooring at various temperatures and humidity conditions can be in NWFA’s Wood Flooring Installation Guidelines and Methods handbook and elsewhere online.

As a rule of thumb, try to avoid installing new floors during bouts of extreme weather such as a snowy winter, when humidity is too high, or a dry summer, when the humidity is too low. Spring and fall have less fluctuations in humidity levels and are more ideal. Follow the manufacturer’s recommendations closely so you don’t lose your warranty coverage.

For best results, the flooring should be conditioned at indoor temperatures of 60 to 80°F and 30 to 50% relative humidity levels. If the conditions are not in this range, turn on air conditioning or heat five days before installation and keep it on for 5 days after installation is complete. This ensures that the flooring is acclimated within an environment that is close to the living one.

Once the environment is within ideal temperature and humidity range, bring in the wood and break the units into smaller sections. Open the packaging and cross-stack the planks with .75 to 1” spacers so that air can reach the board on every side. Use a moisture meter to determine the moisture content of the wood and then continue to take moisture readings every day until EMC is reached.

Proper acclimation can ensure your floor installation is successful, so it’s a process that you should never skip.