Hardwood Floors: Temperature and Humidity
Updated: Feb 7
Wood is a popular material for furniture, flooring, and construction due to its durability and natural beauty. But did you know that the temperature and humidity of your environment can have an impact on how your wood planks look? Let’s explore the science behind this phenomenon and how you can protect your wood plank investments.
How Temperature & Humidity Affect Wood Planks
Wood planks are made of cells that expand or contract when exposed to moisture. When a plank is exposed to higher temperatures, it absorbs more moisture from the air, causing it to swell up. On the other hand, cooler temperatures cause the wood plank to contract as it releases moisture back into the air. Similarly, when the relative humidity in a room increases, more moisture is absorbed by the wood planks in that space which causes them to swell; conversely, low levels of humidity will cause the planks to shrink.
Heat Transfer and Wood
In order to understand how hardwood planks react to changes in temperature and humidity, it's important to understand the basic principles of heat transfer. Heat is transferred by radiation, convection, conduction, and evaporation. Of these four forms of heat transfer, conduction is the most important when it comes to understanding how hardwood planks react to external temperature changes.
When temperatures increase or decrease outside, conduction causes heat to be conducted from one area to another—in this case from the surrounding atmosphere into the plank. This leads to a change in temperature within the plank, which then causes it to expand or contract accordingly. The amount of expansion or contraction depends on how much energy is being transferred from the atmosphere into the plank—the more energy that is being transferred, the more drastic the expansion or contraction will be.
Humidity and Wood
In addition to temperature changes, humidity can also affect how a hardwood plank reacts. When there are high levels of moisture in the air (high humidity), water molecules will be drawn into wood fibers due to osmosis (the movement of liquid through a semi-permeable membrane). As water molecules enter wood fibers they take up space within them and cause them to expand towards the edges—which results in an overall increase in size for the plank as a whole. Conversely, when there is low humidity (low moisture levels) water molecules are drawn out of wood fibers via osmosis to the center—causing them shrink and resulting in an overall decrease in size for the plank as a whole.
The result of these changes in temperature and humidity is a warped or bowed appearance in your wood plank floors or furniture surfaces. While this type of warping can be prevented with proper environmental control measures such as installing humidifiers or dehumidifiers in your home or office space, there are still steps you can take if you already have a warped plank surface by consulting NWFA Hardwood professionals.
All wooden material is affected by changes in temperature and humidity levels, but thankfully, there are ways to mitigate these effects such as controlling environmental factors by installing humidifiers/dehumidifiers and using fans around potential problem areas as well as maintaining a stable temperature throughout your home. With some knowledge about how wood behaves under certain conditions and some preventative measures taken ahead of time, you can ensure your beautiful wooden floors remain flat despite external changes