First and foremost we recommend that all installers are or become certified by the NWFA for installing Solid Wood Flooring.
The National Wood Flooring Association (NWFA) describes acclimation as allowing the moisture content to adjust to “normal living conditions” at the site.
“Normal living conditions” is the average moisture content inside the home throughout the entire year.
For example, if the inside temperature and relative humidity during the winter is 30% rh and 70 F (a moisture content of 6.2%) and during the summer it is 45% and 70 F (a moisture content of 8.5%) you should acclimate the flooring to 7.35 % before installing the floor. For the wood to equilibrate to 7.35% it would require a consistent inside relative humidity of 37% and a temperature of 70 F.
So to acclimate you must first know the average rh and temp for the year and set the inside conditions to match that average.
Every home is different and every areas is different, so knowing the living conditions in all seasons is a must.
Take the flooring out of the boxes for acclimation and SAVE THE BOXES until the job is complete. We recommend leaving the flooring as packed but remove from the boxes as you stack the flooring for maximum air flow exposure.
Take moisture content readings until 90% of your readings, of the floor, are within 0.5% of the average.
In the example above the average was 7.35% so 90% of the readings should be between 6.85-7.85%. Many people will ask how long it takes to acclimate. The answer is, “it depends”. As a rule of thumb, the more dense the wood the longer it will take, but use the method above to know the correct time to start the installation. Any other way and you are taking the chance and assuming the risk.