The Impact of Humidity on Wood Floors

By: Evan Scoboria, Last updated: June 28, 2023

As you admire your wooden floors' natural beauty and timeless elegance, it's vital to understand how various elements, including humidity, can impact their lifespan and appearance. Fluctuations in moisture can lead to significant issues such as warping, cracking, or even splitting your wood floors. This article aims to provide an in-depth understanding of how humidity influences wood floors, the ideal humidity ranges for different types of wood, and how to maintain those optimal conditions. You'll also learn about the effects of high and low humidity on wood and find answers to frequently asked questions about wood floor care. Read on to ensure the longevity of your wood floors and preserve their appeal for years to come.

Wood Floors

Understanding Humidity and Wood

Wood and humidity share a complex, dynamic relationship. Being a natural, porous material, wood is known to be hygroscopic. This term means that wood can absorb moisture from the air in humid conditions and release moisture in dry conditions. This equilibrium with the surrounding environment causes wood to expand or contract, known as swelling and shrinkage.

In an environment with high humidity, wood absorbs the excess moisture, which leads to expansion. This is because the water molecules fit into the spaces between the wood cells, increasing the volume of the wood. If the wood absorbs too much moisture, it can lead to problems such as warping, cupping, or buckling, which occur when the shape of the wood changes due to the uneven absorption of moisture.

Conversely, in a low-humidity environment, wood releases moisture to attain equilibrium with the surrounding air. This moisture loss causes the wood to shrink, resulting in gaps between the planks, cracks, or even splits.

Therefore, maintaining a stable indoor humidity level is crucial for preserving wooden floors' structural integrity and aesthetics. Wood is not just dead material but a living, breathing entity continuously interacting with its surroundings. Understanding this interaction is critical to maintaining and caring for your wooden floors.

The Ideal Humidity Range for Wood Floors

The ideal humidity range for wood floors is between 30% and 50%. This is the range in which wood flooring is likely to maintain its best form, minimizing the risk of distortion and damage. In terms of temperature, the optimal range is typically between 60 and 80 degrees Fahrenheit.

Within this range, the moisture content of the wood stays relatively stable, preventing significant expansion or contraction. Keeping the indoor humidity within this range will help avoid problems such as warping, buckling, cupping, or gapping, which can detract from the floor's visual appeal and pose potential tripping hazards.

It's important to understand that different types of wood may have slightly different ideal ranges, depending on their natural properties and the climate in which they were grown. Always refer to the manufacturer’s guidelines or consult with a flooring professional to understand the specific needs of your particular flooring.

Maintaining your home's humidity within this ideal range preserves your wood floors and creates a comfortable living environment for you and your family. And remember, sudden changes in humidity are particularly harmful to wood floors, so aim for gradual changes whenever possible.

Air conditioners, heaters, humidifiers, or dehumidifiers can help regulate indoor humidity levels, especially in seasonal extremes. A dehumidifier or air conditioner can help extract excess moisture in humid climates or seasons. Conversely, a humidifier can add moisture in drier conditions to prevent your wooden floors from drying out and shrinking.

Regular use of a hygrometer, a device that measures relative humidity, can also be very useful in monitoring and managing your home's humidity levels, ensuring the longevity and beauty of your wooden floors.

Humidity Impact Based on Wood Types

Different types of wood can perform differently under various humidity levels. This is because each type of wood has a unique density, grain structure, and oil content, which can influence how it responds to moisture. Here are some examples:

  1. Hardwoods like oak, maple, and walnut are generally more resistant to humidity changes than softwoods. They tend to expand and contract less with changes in moisture levels, making them a good choice for regions with sizeable seasonal humidity changes.

  2. Softwoods like pine, cedar, and fir are more susceptible to humidity changes. These woods absorb and lose moisture rapidly, leading to more noticeable expansion and contraction. In regions with high humidity, these types of wood may require more maintenance to prevent warping and cracking.

  3. Some tropical hardwoods like teak and mahogany are known for their exceptional resistance to humidity. They have naturally high oil contents, which help repel water and resist changes in size and shape.

  4. Made from layers of wood glued together, engineered wood tends to be more stable in varying humidity conditions than solid wood.

However, no matter what type of wood is used, it's crucial to maintain a relatively stable indoor humidity level. Abrupt or extreme changes in humidity can cause any wood to warp, crack, or split over time. Monitoring and adjusting the humidity levels in your home, especially where wood floors are present, can significantly enhance the longevity and appearance of the flooring. It's recommended to keep indoor humidity levels between 30% and 50% for the best results.

The Impact of High Humidity on Wood Floors

High humidity can have profound effects on wood floors. Wood is a hygroscopic material that naturally absorbs moisture from its surroundings. When the surrounding air is humid, wood absorbs this moisture and swells in size.

When your wooden floors absorb too much moisture, it can lead to distortion and damage, including cupping, crowning, and warping. Cupping happens when the edges of the floorboards rise higher than their center, giving a concave appearance. This distortion occurs due to an imbalance in the moisture content between the top and bottom of the wood. Crowning is the opposite of cupping, where the center of the floorboard swells and rises higher than the edges. This typically occurs when the floor is sanded too soon during the cupping phase or if there's prolonged exposure to high humidity. Warping happens when the floorboard distorts more complexly, often twisting or bending.

Beyond physical distortion, high humidity can encourage the growth of mold and mildew on your wooden floors, presenting a risk to your home's cleanliness and even the health of its inhabitants. These fungi thrive in damp environments and can quickly colonize your floors if consistently exposed to high humidity.

Furthermore, these effects are not just cosmetic. Damaged and distorted floorboards can be a tripping hazard, compromising the safety of your home. They can also be costly to repair or replace and, in some cases, may necessitate the replacement of your entire flooring.

Controlling the humidity level in your home, especially during the more humid months of the year, is crucial in preserving the quality and longevity of your wood floors. This might involve using air conditioners or dehumidifiers, improving ventilation, or installing a whole-home humidity control system.

The Impact of Low Humidity on Wood Floors

Just as high humidity levels can wreak havoc on your wood floors, low humidity levels can also pose significant problems. When the air is too dry, wood can lose its natural moisture to the surrounding environment to equalize the moisture levels. This can result in various undesirable changes and damages to your wood flooring.

Shrinking is one of the most common issues associated with low humidity levels. As the wood loses moisture, it contracts, causing gaps between the floorboards. While minor gaps can be a natural occurrence during the drier months of the year, excessively wide or persistent gaps can lead to instability in the flooring structure and can be unsightly.

Dry conditions can also make your wooden floors more prone to splitting and cracking. As the wood dries out, it can become brittle and weak, leading to structural damage that affects not only the appearance of your floors but also their longevity and durability. In severe cases, these cracks may necessitate expensive repairs or replacements.

Another concern is the issue of "checking." This term refers to small splits that appear on the surface of the wood, typically at the ends of the floorboards. These can be small enough to go unnoticed initially but can grow over time, especially if the low humidity conditions persist.

Moreover, low humidity can lead to your wood floors' dull, lifeless appearance. The lack of moisture can strip the wood of its natural luster and vibrancy, leaving your floors aged and worn out.

Just like in the case of high humidity, it's crucial to control the humidity level in your home to prevent these problems. Using humidifiers, especially during the drier months, can help maintain optimal humidity for your wood floors. Other strategies include sealing your home against drafts, installing weather-stripping, and using moisture-retaining products for wood care.

How to Maintain Optimal Humidity Levels for Wood Floors

Maintaining optimal humidity levels for your wood floors is crucial to ensuring their longevity and preserving their aesthetics. Fortunately, there are several strategies you can implement to achieve this balance:

  1. Monitor Humidity Levels: The first step is to check the humidity levels in your home regularly. This can be easily done with a hygrometer, a device that measures the amount of moisture in the air. Aim to keep humidity between 30% and 50% for the best results.

  2. Use a Humidifier or Dehumidifier: Depending on your region's season and climate, you might need to add or remove moisture from the air. A humidifier can help add moisture during the dry months, whereas a dehumidifier can help remove excess moisture during the humid months.

  3. Ventilate Your Home: Good ventilation can aid in maintaining proper humidity levels. Use exhaust fans in the kitchen and bathrooms to remove moisture-heavy air. Regularly opening windows can help circulate fresh air and stabilize indoor humidity levels.

  4. Consider an HVAC System: Modern HVAC systems can regulate your home's temperature and humidity levels. If humidity control is a significant issue in your home, consider investing in an HVAC system with built-in humidification and dehumidification controls.

  5. Seal Your Home: Prevent outside air from influencing indoor humidity levels by sealing gaps in windows, doors, and walls. Weather stripping and caulking can provide a more efficient seal.

  6. Care for Your Floors: Regularly clean and polish your floors as recommended by the flooring manufacturer or your professional installer. Certain wood care products can add moisture to wood floors, preventing them from drying out and cracking.

Remember, every home and climate is different. What works best for your wood floors may vary, so seek professional advice if you're unsure. Consistent attention and care to humidity levels can ensure that your wood floors remain beautiful and strong for many years.

Frequently Asked Questions

How Does Humidity Affect Wood Floors?

Humidity has a direct impact on wood floors. When the air is too dry (low humidity), wood can shrink and cause gaps between floor planks. On the other hand, when the air is too moist (high humidity), wood can expand and cause the planks to buckle or warp. Therefore, maintaining a balanced indoor humidity level is crucial for the longevity of wood floors.

What is the Ideal Humidity Level for Wood Floors?

The ideal humidity level for wood floors typically falls between 30% and 50%. This range ensures the wood does not dry out, shrink, or absorb too much moisture and swell. However, the specific ideal range can depend on the type of wood and the manufacturer's instructions.

How Can I Monitor the Humidity Levels in My Home?

You can monitor the humidity levels in your home by using a hygrometer, a device that measures the amount of moisture in the air. Some HVAC systems also come with built-in humidity monitors. It's a good idea to regularly check these readings to ensure the humidity levels are within the safe range for your wood floors.

Can I Use a Dehumidifier or Humidifier to Control the Humidity Levels?

Yes, using a dehumidifier or humidifier can effectively control the humidity levels in your home. A dehumidifier can help to remove excess moisture during the humid months, while a humidifier can add needed moisture during the dry months.

What Happens if My Wood Floors Are Exposed to High Humidity Levels?

High humidity levels can cause wood floors to absorb moisture, leading them to expand. This can result in issues such as cupping, where the edges of the wood planks rise higher than the center. If left unchecked, high humidity can cause severe damage to wood floors.


In conclusion, the impact of humidity on wood floors is a crucial aspect for homeowners. Understanding how humidity levels affect wood, recognizing the signs of excessive moisture or dryness, and maintaining an ideal humidity range can ensure their wood floors' longevity and aesthetic appeal. Despite the challenges, with the proper care and preventative steps, it is possible to manage and even prevent the adverse effects of humidity on your wood floors. Your efforts in understanding and controlling the humidity levels will lead to many years of enjoying the warmth and beauty of your wood floors.