How to Acclimate Wood Flooring

Whether you’re a DIY homeowner, contractor, or flooring pro, it pays to know the ins and outs of hardwood floor acclimation.

Wood is hygroscopic, meaning it absorbs or releases moisture to stay in equilibrium with its surrounding environment. That’s why floorboards require proper acclimation—allowing enough time for the wood to adjust to the ambient conditions of its new home. This will keep the floor less susceptible to moisture damage even after installation.

Knowing and planning for the acclimation process leads to smoother, faster, and higher-quality work. And this isn’t just true for hardwood floors—it’s true for softwood and engineered wood floors, too.

So let’s talk about acclimation how-tos and best practices:

• How to prepare the installation site
• How to acclimate hardwood flooring
• How long floorboards take to acclimate
• Tools you need for accurate acclimation

By taking this thorough approach to optimal wood floor acclimation, your customers will be sure to thank you for a job well done.

How to Prepare the Installation Site

Even if your new floors haven’t yet arrived at the installation jobsite (either by your clients, yourself, or a third-party delivery company), there’s plenty to do to prep the area for proper acclimation.

Stabilizing the ambient conditions at the installation site goes a long way in helping the floorboards acclimate more quickly and smoothly.

Keep these two moisture sources in mind:

• Moisture intrusion from leaks, rain, or the subfloor
• Moisture from changes in humidity levels

You can prevent moisture intrusion by making sure that:

• The building is enclosed. This safeguards against leaks and inclement weather.
• The final grading is complete, and all drainage runs away from the building.
• The wet construction elements are completed and dry, such as concrete and plastering. If building materials in the surrounding environment are dry, you won’t have to worry about excess moisture absorbing into your floorboards.
• Basements and crawl spaces are dry and moisture-controlled: Even if these spaces are only slightly damp, that’s enough to affect the flooring material above them.
• The subfloor is free of excess moisture: Make sure to measure subfloor moisture, because in most cases, if the subfloor isn’t within 2-4% of the final moisture content (MC) of the wood planks, the moisture the subfloor releases could cause floorboards to shift, warp, or swell.

  (Note: Whether the subfloor differs from the hardwood by 2% or 4% depends on the thickness of the hardwood material you’re using. Thin planks measuring thinner than 76 mm should not differ more than 4%, and thick planks that measure thicker than 76 mm should not differ more than 2%.)

Meanwhile, you can prevent moisture changes from humidity levels by:

• Maintaining consistent climate control for at least two weeks before the boards arrive: This ensures that the environment matches normal living conditions and that no unexpected fluctuations will end up prolonging acclimation time. Set HVAC accordingly, and if the area needs a little extra help, try bringing in extra fans, portable air conditioning, space heaters, dehumidifiers, or humidifiers.

  Generally, normal living conditions are considered to be 60-80 degrees Fahrenheit and 30-60% relative humidity. This may vary, though, depending on the climate of your location.

For the best results, ensure the room’s moisture levels stay consistent throughout the acclimation process.

How to Acclimate Hardwood Flooring

Acclimation is a natural process. This means no matter what environment it’s placed in, the wood will adjust its moisture content over time to match its environment.

So, for a wood flooring installation, what matters is that the wood properly acclimates to its new environment before installation begins. And that it has been given enough time to do so.

Otherwise, if hardwood floorboards are forced to acclimate too quickly between significantly different environments, rapid and uneven moisture exchange can stress the integrity of the wood, which could lead to warping, cracking, end checking, and more.

Fortunately, there’s a tried and true process for managing acclimation in a way that’s fast, efficient, and above all, safe for the wood itself.

Here’s how:

1) Unpack and stack floorboards: Hardwood flooring cannot properly acclimate when still in a box or in plastic wrapping. The individual boards need unrestricted airflow. Cross-stack them in layers in your installation zone, placing spacers between the boards to maximize airflow. Then you’ll know they’ll be able to dry faster and more evenly.

 

2) Determine target moisture level: You have to know the wood’s target moisture level because that’s the baseline it needs to reach to be considered fully acclimated. The target moisture level of most floors is between 6-9% MC.

 

However, this may vary depending on the climate of your environment. Make sure you know the equilibrium moisture content (EMC) for the area and the wood species of the flooring material.

 

You can determine the EMC by using this chart.

 

As for floor type or wood species, flooring manufacturers will give you the ideal moisture levels of their floors, whether that’s engineered hardwood flooring or solid hardwood flooring, made of oak or maple. Make sure to look at the manufacturer’s recommendations.

 

3) Measure moisture content with a trusted wood moisture meter: This is the only way to truly verify that the floorboards are indeed at the necessary moisture content. Wood moisture meters come in pin-style or pinless, and we recommend pinless because it’s fast, easy to use, and won’t leave pinholes behind.

 

Pinless meters also make it much simpler to take multiple readings, which you need to do to determine the moisture condition of the flooring. Some floorboards might contain more moisture than others. By measuring several boards, you’ll have a much clearer idea of the big picture.

 

You’ll also want to test the wood multiple times throughout the acclimation process until it’s reached its target moisture level.

But always remember—acclimation is a waiting game. Some flooring may take longer to adjust.

In some cases, you may need to store your floorboards until they acclimate.

How to Best Store Hardwood Floorboards

If the acclimation process looks like it might take a while, you may need to store the wood in a stable environment until it reaches the right moisture level.

Naturally, you’ll want to find an area with good ventilation and consistent temperature and humidity that is as close as possible to the conditions of the final installation site. (Hint: Not the basement or garage, which are more likely to experience varying ambient conditions.)

But realistically, how long should acclimation take?

How Long Should It Take to Acclimate Wood Floors?

Wood floors can take anywhere from two weeks to several months to fully acclimate to their new environment.

Some flooring experts may suggest that only three to seven days are needed to acclimate your floors—and that might be the case, but there are many variables. The time it takes to acclimate will largely depend on the type of wood, the board’s thickness, and the climate of the installation space.

This is because some wood types (like engineered wood flooring) acclimate faster than others, thicker boards take longer to dry, and fluctuating (or high moisture) climates can slow down the acclimation process.

No matter your situation, it’s important not to rush the process. Give your floors the time they need to acclimate. Otherwise, you could run the risk of experiencing moisture-related failures (like buckling, cupping, or crowning) later down the road.

How to Tell if the Flooring Has Sufficiently Acclimated

You can tell if the floorboards have properly acclimated if their MC matches the moisture level of the installation space. To find out, take multiple readings with a trusted moisture meter.

While poorly acclimated boards may become warped or swollen, properly acclimated boards will be free of such moisture issues.

Accurate Acclimation Depends on this Tool

It’s tough to determine when floorboards are sufficiently acclimated if you don’t have a reliable wood moisture meter on hand.

You can do everything else correctly to acclimate the flooring—preparing the space, stacking boards, determining target MC, etc. But all these important steps hardly mean anything without an accurate moisture meter to verify if the wood has indeed reached the correct EMC for the location.

If your moisture measurements are off, you could end up installing flooring that later warps, which could lead to project delays or even project failure.

That’s why the most important part of acclimating wood flooring is finding an accurate wood moisture meter with moisture readings you can count on.

Want to see for yourself how Bessemeter’s accurate, fast, and user-friendly pinless meters can simplify the acclimation process for you?