When it comes to hardwood floors and humidity, winter tends to be the season of choice for discussion. But surely the dog days of summer deserve their due.

If not monitored, winter’s low humidity can create unsightly gaps between your wood floorboards (and you can get your toes stuck in there), but let not the trials of winter fool you; the chilly season is not the only challenge around.

To ensure your wood floors are installed properly or that they stay in tip-top shape, there are some important things to be aware of in the summer when most of us experience the highest humidity levels of the year.

1. Humidity affects different floors differently.

Engineered floor on left, solid floor on right.

The type of wood flooring you have will determine how much risk you face in a high humidity environment.

High humidity poses a greater danger with solid wood when compared with engineered wood.

Regarding a solid wood floor, you need to know if it was installed within the last three years. If so, then it will have a greater reaction to humidity than its older counterparts. This is generally due to the floor settling within its environment. In scientific-speak, the phenomenon is called hysteresis: over several years’ time, the experience of expansion and contraction in flooring due to relative humidity reduces.

As your floor ages, it will continue to expand and contract. However, a great thing about this is that each time it does so, it does so a little less than the time previous. Like you settling into your home with more clarity and happiness, so does the floor!

2. For a new install, take into account proper acclimation.

Figure from Woodcraft Magazine

When you install a solid wood floor, you need to take into account the whole swing of humidity you will experience. Acclimation is key in the summer because wood naturally absorbs its surroundings. Acclimation is the process where the moisture content in the wood (moisture in ratio to the weight of wood fiber) needs to fall within a certain percentage.

If you live in the driest parts of the US, like Utah or Arizona, these moisture content levels can be as low as 4-5% while more humid climates like Florida can reach levels as high as 14%. Most of the country ranges between a 7-9% moisture content.

If you live in an 8% region, then it would not be surprising to receive a floor with a 10% moisture content that would need to acclimate in an air-conditioned home to allow the wood to give out some moisture and drop down into the appropriate 8% range. This is where a professional can help ensure you don’t get an installation that will result in gapping or cupping. We recommend you get assistance from a professional who knows your region and the moisture content recommendations from the National Wood Flooring Association.

3. If you have a crawl space, check for moisture.

Summer is the time of year when everything heats up. If your house has a crawl space, then you should check for excessive moisture. As the ground warms up in the crawl space, moisture will rise and evaporate, causing excessive humidity under the house.

This can create issues such as your wood floorboards growing. Moisture in the crawl space attaches to the bottom of the boards, and those boards grow a little faster than the ones at the top. This is called wet cupping, and you’ll see the edges of your floorboards start to curl up. This can also happen with engineered flooring, but it’s typically not as prominent.

If you are starting to see this type of cupping on a solid wood floor in the summertime, that’s likely due to moisture in your crawl space, and you’ll want to take measures such as using plastic to create a vapor barrier or even incorporating a dehumidifying system if possible.

4. If you have engineered floors, they have a slight advantage over solid wood in the summer months.

Don’t look at the cycle between dry and wet as something you have to fight—it is just something to be aware of and manage. Raises in humidity can be good for your home.

Even in a typical home in a controlled environment, you would expect to see the average humidity rise slightly, and that’s good. Coming out of the dry season, you are now slowly allowing all the wood in your home to take on a little bit of moisture and the wood will relax a little bit. Engineered wood floors are made to be stable and can take swings in low and high humidity without moving very much dimensionally.

Because an engineered wood floor takes on and gives off moisture slowly, you can allow for higher humidity in the home for select, short periods of time without undue damage to the floors. We don’t recommend opening up your windows for a couple days with solid wood, but you can likely get away with some open windows for a short amount of time with an engineered floor.

Engineered wood floors react on averages over three to five weeks while solid wood floors start to move as early as one week. So you have a longer buffer and a larger window of time with engineered flooring.

Variety of flooring options.

Whether you want to weather the summer months with a solid wood or an engineered floor, we have various collections to meet a variety of needs and budgets. For any questions about flooring (or humidity and installations), please contact us today through our website or by phone, 877.215.1831.