.Acclimation, sometimes called conditioning, is the process of allowing wood to reach its equilibrium moisture content (EMC) within “normal living conditions.” It is also one of the most important steps of hardwood floor installation. Not properly acclimating or conditioning wood flooring may cause excessive expansion, shrinkage, dimensional distortion, or even structural damage. Step one is to make sure that the heating and air conditioning units are in operation at least five days before delivery of the flooring, during installation and after the flooring is installed. If it is not possible for permanent HVAC to be operating before, during and after installation, a temporary system that mimics normal living conditions may enable installation to proceed.
Acclimation means knowing the moisture content
An installer without a moisture meter means you need another installer. The entire concept of acclimation is about moisture content, not high or low but at equilibrium. Wood flooring is a hygroscopic material subject that expands or contracts with the amount of moisture, temperature, and humidity within the surrounding environment. Wood flooring simply needs to reach moisture content level in equilibrium with the surrounding environment (EMC) where it will be installed. The process of reaching this equilibrium, where all the boards read the same level is defined as acclimation.
Acclimation is not about a specific number of days
The acclimation process is not about just time. It is more a matter of waiting to achieve results, rather than waiting until a certain number of days or weeks has passed. Factor the species of wood, the room temperature, relative humidity, and moisture content of both the flooring and the environment. Acclimate the materials as long as necessary to accomplish this task, taking the necessary moisture readings to indicate when the materials have reached the proper moisture content and when no further changes occur.
Plan for the acclimation process
Remember that hardwood loses moisture and shrinks in dry climates, and expands in humid climates. Ensure that you allow your hardwood to acclimatize to the moisture content and temperature of its new home before installing it. This process takes at least two weeks, sometimes longer, so do not rush into installing a wood floor. The last thing you want is to install a new hardwood floor and have the wood shrink or expand after installation.