The Effects of Humidity on Hardwood Floors

July 14, 2021

As Texans, we experience our fair share of seasonal humidity, especially during hurricane season. While most think of humidity as it relates to the comfort of one’s home, it can also have adverse effects on hardwood flooring.

Depending on the type of hardwood floor, if its construction is that of natural wood, improper humidity levels can impact it in various ways.

Ideal Humidity Levels

So, what qualifies as a healthy indoor air quality? There are three components: fresh, clean, and proper humidity levels. As an overall benchmark, the ideal humidity level for a home is around 40-50%.

  •  Winter Months: Depending on winter weather patterns in your area, 30-40% humidity will help prevent condensation build-up on windows and doors. You’ll want to be careful not to lower it too much to avoid upper respiratory illness and asthma.
  • Summer Months: Humidity levels in the summertime can move upward to 50-55%. Going too high can cause an increase in mold growth, bacteria, and viruses.


Healthy Humidity Levels for Hardwoods

Normal humidity levels for optimal performance and longevity of your hardwoods can range from 30 to 50%. Here’s a breakdown of levels per hardwood product.

              Solid Hardwoods: 35 to 55%

              Engineered Hardwoods: 35 to 65%

Dry Season

During the winter months, dry air can develop due to heating your home to stay warm. Dry air causes hardwoods to contract, resulting in the following visible issues.

Gapping: When the humidity in your home is lower than expected, wood planks can shrink, which creates gaps between the planks. Believe it or not, gaps are relatively common during winter months, and when the humidity levels stabilize, the wood plank will expand, filling the space.

Splits: Wood can crack and split when faced with extreme environmental conditions. It can become brittle and easily damaged. Visible signs are cracking along the grain, which leaves the wood unprotected.

Tips for preventing dryness:

  • Make sure your humidity levels are within the parameters previously mentioned.
  • If using a wood stove or electric heater, use a humidifier to reduce the dry air.
  • If leaving your home for extended periods of time, make sure to check your humidity levels and keep them in range before leaving.


Humid Season

During warmer months of the year, humidity is more likely to wreak havoc on your floors. The moisture is absorbed through the hardwood planks, causing a number of issues.

Cupping: With excessive humidity levels, planks can cup as their edges become higher than the center. It’s most commonly seen in basements or crawl spaces. To combat cupping, use a fan or a dehumidifier to remove the moisture in the air.

Crowning: Crowning is the opposite of cupping. You’ll see the middle board raise up above the edges. This happens if the top of the plank is sanded too soon after cupping.

Buckling: One of the most extreme reactions to moisture is buckling. This occurs when the floor expands beyond the space of the gaps, causing it to rise several inches off the subfloor. As the humidity levels stabilize, the floor may go back to normal, but the spacing between boards may not return to what it was previously.

Cracking: With excessive humidity, hardwood planks will start pressing against one another. This can cause the structure of the board to be compromised under stress, creating cracks.

Tips for Preventing Moisture Issues:

  • Leave a free expansion space around the edges of your flooring. The edges are usually covered with baseboards so that you won’t see the gaps.
  • Be humidity aware and maintain proper levels in your home.
  • If you leave your home for extended periods of time during the summer, leave the A/C on.
  • Avoid exposure to water during inclement weather periods.
  • Clean your hardwoods according to the manufacturer’s recommendations.
  • Choose a quality engineered hardwood that fits you and your family’s needs.


If you’re ready to invest in hardwoods or need help repairing your current flooring, feel free to schedule a consultation with us! We have many financing options available to help make your flooring dreams a reality.

If you’re looking for more inspiration, feel free to head on over to the flooring section of our website. And, stay up to date on the latest and greatest news from Flooring Design Center by following us on Facebook and Instagram.