Acclimation of Hardwood Flooring

Part I – General Acclimation Guidelines

(For a more detailed discussion of acclimation issues, See Appendix B.)

A. Storage and Conditions

1. Do not store wood flooring at the jobsite under uncontrolled climate conditions. Garages and exterior patios, for example, are not acceptable areas to store wood flooring.

2. Ideal interior climate conditions vary from region to region and jobsite to jobsite. It is your responsibility to know what your “ideal” climate conditions are and build your floor around those conditions. For a general view of moisture-content averages by region, refer to Appendix D and Appendix E.

B. Acclimation

Note: Some manufacturers do not require acclimation for certain products prior to installation. If the manufacturer recommends that the wood flooring be acclimated before installation, proceed as follows:

1. Ensure that the building is enclosed.

2. Verify that the building is maintained at normal living conditions for temperature and humidity.

3. Where building codes allow, permanent heating and/or air-conditioning systems should be operating at least five days preceding installation to promote proper acclimation. For radiant heat see Appendix H.

4. If it is not possible for the permanent heating and/or air-conditioning system to be operating before, during and after installation, a temporary heating and/or dehumidification system that mimics normal temperature and humidity conditions can enable the installation to proceed until the permanent heating and/or air-conditioning system is operating.

5. Upon delivery, check wood flooring moisture content with a moisture meter to establish a baseline for required acclimation. Check the moisture content of multiple boards. A
good representative sample is typically 40 boards for every 1,000 square feet of flooring. Acclimate to manufacturer’s recommendations or as necessary according to geographical location and your jobsite location.

6. Prior to installation, ensure that wood flooring is within acceptable range of moisture content with the wood subfloor. For solid strip flooring (less than 3” wide), there should be no more than 4 percent moisture content difference between properly acclimated wood flooring and subflooring materials. For wide-width solid flooring (3” or wider), there should be no more than 2 percent difference in moisture content between properly acclimated wood flooring and subflooring materials.