At Last, The Secret to Acclimating Hardwood Floors Is Revealed!

At Last, The Secret to Acclimating Hardwood Floors Is Revealed!

Have you ever stepped out of a nice, air-conditioned building and into a hot, muggy day? Your body must adjust to the new humid environment. It’s the same for wood flooring, but the process is gradual.

Wood flooring does need time to acclimate to your location before you can install it. If you don’t, you could end up with cupped or warped hardwood floorboards within a few weeks of installation. Your expensive new hardwood floor will look like salvage from an old mining shack or sunken ship.

Fear not! You’re about to learn everything you need concerning wood floor acclimation.

What Is Wood Floor Acclimation?

Acclimation is the process of allowing the hardwood floor planks to adjust to the new environment. The purpose is to allow the moisture content of the wood to match the surrounding conditions of the room. 

The best practice is to have the wood flooring moisture level within 4% of the subfloor. For solid wood planks wider than 3 inches, the flooring should be within just 2% of the subfloor.

Why Does Wood Flooring Have to Acclimate?

Wood is a natural, porous product that expands and contracts due to variances in humidity. Before installing a wood floor, the 

wood needs to reach a moisture content equivalent to normal living home conditions. 

Failing to acclimate hardwood floors properly may cause excessive expansion or shrinkage. The results are an uneven, terrible-looking floor. Depending on the moisture level, the wood can warp or shrink so severely that the gaps will make the floor look like bathroom tiles and possibly cause permanent damage to the wood. 

Let’s say you live in the dry, hot Tucson, Arizona. If your new hardwood floor ships from an unheated warehouse in Chicago in January, there will be approximately a 30-degree temperature difference and a 30% drop in humidity from north to the southwest. Installing these boards immediately without acclimating them first would be a disaster. 

Hardwood flooring is a hygroscopic material. That means it releases moisture during the winter heating months when humidity is low and absorbs moisture during the humid spring and summer months. The room’s air humidity directly affects the wood’s moisture content. 

The HVAC system plays an essential part in keeping wood floors at a consistent moisture level. 

You want the floor’s moisture to equalize with surrounding temperature and relative humidity (RH). Flooring experts say fully acclimated hardwood floors have a 6.9% moisture content in a 70°F and 35% RH environment. Hardwood that has adjusted to 70°F and a higher 50% RH will have a 9.2% moisture content. You can see the chart below how that works. 

moisture contents of wood at various temperatures

Let’s look at an example using maple wood. 30% to 50% RH is the most comfortable humidity range for indoor environments like a basketball arena or a living room. The Maple Flooring Manufacturers Association’s (MFMA) specification for kiln-dried maple boards is 6% to 9% moisture content. Their members will reject wood outside of that range to manufacture hardwood flooring. 

What Happens If You Don’t Acclimate Hardwood Floors?

Here are a few of the symptoms that can occur.

acclimate hardwood floors to avoid buckling

– In extreme cases, the wood plank pulls away from the subfloor. 

Cupping – As the name implies, the edges curl up higher than the center, creating a cup-like appearance. 

Crowning – This symptom is the opposite of cupping. The center is higher than the edges creating a speed bump.

Warping – This results in a twisted board with raised edges that are no longer straight. 

If the moisture content is too high while installing the floor, the boards will eventually shrink, causing unsightly gaps and making the floor look unfinished.

By acclimating the floor, you create a balance of moisture in the wood flooring and the room’s environment. This way, the wood floor stays straight and flat all year long.

How Long Does Hardwood Flooring Need to Acclimate Before Installation?

Always consult with the manufacturer to see what they recommend. Typically, you want to acclimate hardwood floors for at least three days minimum. 

That said, some flooring installers don’t recommend acclimating at all if the wood meets specific guidelines. Check the moisture of the subfloor and wood floor. You don’t have to acclimate if:

  1. The moisture level between the two floors is within 2% to 4% and...
  2. Both floors have moisture levels of 12% or less and...
  3. The temperature is over 60°F (15.5°C) or below 80°F (26.6°C) can install without problems. 

How Do You Acclimate Hardwood Floors?

Your wood flooring needs the same temperature and humidity as you. Usually, you want the room to stay at an even humidity level between 30% to 50% all year long. Likewise, keeping the room’s temperature between 60° and 80° Fahrenheit means you’ll be comfortable, and the wood floor won’t expand or shrink excessively. Always check with the manufacturer for your specific species of wood floor for the optimal levels.

So, how do you acclimate wood flooring? It’s a simple six-step process that takes some patience.

Step 1 – Turn on the Heat or A/C

If it’s an unoccupied space such as a new home, turn on the air conditioning or the heating at least five days before the flooring gets delivered. You want the home to be at a typical temperature and humidity for that time of year. 

If the permanent HVAC hasn’t been installed, rent a portable heater or air conditioner until the permanent system comes online. 

Step 2 – Receive the Shipment

Once the home’s humidity and temperature have stabilized, proceed with the delivery of your flooring material. Rent, buy or borrow a moisture meter to check the moisture content as soon as it arrives. If you’re not familiar with this tool, watch this video, “What is a moisture meter?” 



Step 3 - Check the Subfloor’s Moisture

As we’ve mentioned, the subfloor’s moisture content should be 12% or lower and within 2% to 4% of the new floor. If the subfloor has a high moisture content, you will need to dry it out before installing the floor. 

There are different options for checking subfloor moisture depending on whether it’s concrete or wood. This video, “Subfloor Moisture & Hardwood,” will demonstrate the tools and techniques.



Step 4: Install or Acclimate

If both floors have the correct moisture levels, you can proceed with the installation. Otherwise, you need to acclimate until it does. 

How Do You Stack Hardwood to Acclimate?

For best results, don’t store acclimating floorboards inside the boxes or stacked one on top of the other in tall piles. The best practice is to arrange boards staggered in layers, so the surface of the wood gets equal exposure on all sides.

Wait until the moisture meter indicates that they have achieved moisture equilibrium with the subfloor, which can be up to three days.

One way to speed up the wood floor acclimation process is to break the shipment into smaller lots. This will increase airflow and surface area exposure to the environment. Cross-stacking individual planks with spacers between layers improve circulation. You can see this technique in the 1-minute video, “Flooring Preparation - How To Acclimate Hardwood Flooring.”



Can Hardwood Flooring Acclimate in the Box? 

It is possible to acclimate hardwood flooring in the box, but it will take much longer due to the lack of air circulation. How long to acclimate hardwood flooring in the box depends on the room, how it’s stacked, and the amount of wrapping.

wood floor acclimation

If you have the time and space to store the boxes, remove both ends and any plastic wrap from the wood. Cross-stack the boxes, leaving spaces between them. Keep the boxes in the same room you plan to install the flooring or somewhere with a similar temperature and humidity level. 

Bear in mind that this applies to engineered wood flooring as well. 

How Do You Acclimate Engineered Flooring?

Engineered hardwood flooring has a plywood or synthetic core, making it more dimensionally stable than solid hardwood floors. It’s more resistant to possible expansion or contraction due to humidity changes. However, manufacturers still recommend acclimating engineered hardwood floors for at least 48 hours or until they reach moisture stability in the top wood veneer or plywood core. 

Check with your engineered floor manufacturer for recommendations and instructions as to how to acclimate their product. 

Does Engineered Hardwood Expand and Contract?

Most engineered wood floors have plywood cores, with the grain running perpendicular to each other on alternating layers. The top is a solid wood veneer. Although the plywood makes the plank more directionally stable, it is still wood. It is subject to the same seasonal changes and humidity as hardwood. Engineered floors do expand and contract like solid wood floors, although not as much. 

Does Engineered Hardwood Need to Acclimate?

Most experts say to acclimate the planks for two days, as we mentioned above. If the moisture level between the subfloor and engineered floor is less than 4%, you can install it right away. 

In a Hurry? Install a Prefinished Floating Floor

A prefinished floor has multiple coats of finish that are already dried and cured. The moment you lay them down, you can use them. 

When you opt for a floating floor like EasiKlip, there are no adhesives that must dry. It installs without glue, screws, or nails. Plus, they are prefinished and ready to go. Because they are solid, 3/4-inch white oak, you still need to acclimate them as described above. 



As an Amazon Associate, Easiklip Floors earns from qualifying purchases. This helps us provide more great blog content. Thank you for your support.

Previous Post Next Post

  • Easiklip Floors - Harry Chu