Does Wood Expand in Cold Weather?

If you buy something through our posts, we may get a small commission. Read more here.

The winter season ushers in numerous festivities and celebrations, yet it can also pose challenges for your wood furniture, wooden doors, and possessions. A common belief among many is that wood expands in cold weather. But is this assertion accurate?

In this informative guide, I will delve into this matter, providing valuable insights and practical tips to help you safeguard your wooden belongings during the winter months.

How Does Cold Weather Affect Wood?

The impact of temperature on wood is not usually direct. However, its shapes and dimensions are mainly influenced by wood moisture capacity changes. Thus, wood expands when moisture increases, while decreased moisture leads to contraction.

In addition, furniture made from solid wood can be susceptible to warping and cracking as a result of these changes in moisture level. As long as there are no frequent fluctuations between high and low temperatures, wood will not suffer any negative effects from cold weather.

What Will Happen to Wood When Exposed in the Cold?

Wood can experience changes in size during colder months due to fluctuations in its content in moisture; dry air has less moisture, leading to the release of some moisture from the wood to maintain its equilibrium moisture content (EMC). 

expanding wood

Conversely, damp cold air has more moisture, causing the wood to absorb as much moisture, thus, resulting in warping and swelling of the wood. Furthermore, in freezing weather, water inside the fibers’ wood also freezes, which can cause them to separate and expand.

How About Wooden Floors and Doors in the Cold?

The extent to which wood expand and contract during winter depends on a range of factors related to cold weather conditions.

In winter, the atmosphere typically has reduced moisture levels, causing the wood to release moisture into the air to achieve an equilibrium moisture content appropriate for the low humidity conditions. 

Thus, this moisture release can lead to the wooden floors and doors’ contracting and shrinking due to reduced moisture levels. 

However, one should consider the precipitation in the form of snow and rain during winter, especially for outdoor wood furniture and flooring, including wooden doors. If wood floors or doors absorb moisture excessively, they are prone to expansion.

moist deck

For example, when you hang your wet coat on your wooden door, it can absorb moisture coming from your coat, which can cause the expansion of the wood. 

In addition, similar to wooden furniture, wood flooring also undergoes expansion during summer. To conclude, cold weather can cause the expansion and contraction of your wooden floors and door.

How Long Does it Take for Wood to Expand?

Wood expands and wood contracts because it can absorb moisture and hold water, which makes it vulnerable to variations in humidity levels. This is why it is referred to as a hygroscopic material.

Wood density affects how quickly moisture can penetrate the wooden surface. Thus, high-density hardwoods take longer to absorb moisture, while low-density softwoods have a porous material that allows them to absorb moisture faster.

In addition, when the humidity levels decrease, less dense wood releases moisture at a faster rate than those hardwoods due to their lower stability. 

wooden table

However, each wood species has limits on how much it can expand and how much moisture it can absorb. Thus, it is important to note that the moisture level of wood cannot go beyond fifty percent to avoid extreme expansion and contraction.

When Does Your Wood Expand?

Wood typically undergoes expansion primarily as a response to seasonal changes. However, it’s important to note that other factors can also contribute to this phenomenon.

For instance, wood might expand not only due to seasonal variations but also because of leaks or sudden shifts in temperature and moisture levels.

Wood has the propensity to enlarge in hot weather. Thus, wood expands by up to 50% of its overall potential for wood movement during fall and spring, followed by a subsequent contraction of the same magnitude.

Due to the hot weather, wood expands during the summer months of June to July and until August. Also, wood tends to experience the most expansion during this time. Which can be one of the hardest times for your wood furnishings, wooden door, and other wood pieces.

crack on wood due to cold

To prevent harm to your wood floors or furnishings, it’s crucial to comprehend the mechanisms behind the expansion and contraction of wood. With this knowledge, you can anticipate when these changes may occur and implement measures to safeguard your valuable wood pieces.

Will it Expand At Night?

Wood undergoes a slight expansion during nighttime. This occurs because the relative humidity in the air outside is higher than the humidity within the wood at night, causing moisture to seep through the wood’s pores during this time.

In addition, moisture infiltration causes the cell fibers’ enlargement and swelling, leading to an expansion of the wood during the night.

Will it Expand During the Monsoon?

During the season of monsoon, the wood undergoes thermal expansion as the atmospheric humidity exceeds the moisture level within the wood. 

staining old deck

Furthermore, water molecules have the ability to pass through the pores of wood, infiltrating the material and equalizing the difference in humidity between its interior and exterior. 

As a consequence, moisture can lead to the swelling of wood fibers, resulting in the expansion of wood during periods of increased humidity, such as during the monsoon season.

Expansion of Wood in Winter + How Long Will It Take to Expand

In freezing or cold temperatures, the water in the wood fibers expands, separating them as it freezes. Furthermore, the winter season is characterized by higher atmospheric humidity levels of 76% compared to the summer season, with a humidity level of 66%. 

The difference in humidity levels causes wood contracts or wood shrink and wood expansion. Over time, the repeated process of shrinkage and expansion due to seasonal changes can result in cracks in the wood.

Nevertheless, each type of wood has a particular threshold for moisture absorption and expansion that it can handle. It is crucial to remember that the moisture content will not exceed 50%.

To conclude, wood expands in the winter season. Fortunately, the issue of wood expansion due to temperature changes only pertains to genuine wood. 

Douglas Fir lumber

Thus, those who use wood substitutes like chipboard or plywood must not be concerned about wood expansion and contraction during temperature fluctuations, as these materials are not susceptible to this problem.

How Much Your Wood Can Shrink During Winter

In winter, wood shrinks due to decreased humidity as the air becomes less capable of holding moisture or drier. To prevent wood furniture or wood floors from shrinkage, it is essential to maintain the internal humidity level in your home by using a humidifier during the winter.

Time Of Year Wood Shrinks

In the winter, wood undergoes a total movement allowance that is typically evenly distributed. This movement allowance can result in both wood shrinkage and wood contraction, as the material responds to changes in temperature and humidity.

Does Wood Expand With Moisture or Humidity Levels?

When the temperature changes, wood does expand in cold or warm temperatures, which occurs as the wood absorbs moisture from the air. Furthermore, the excess moisture leads to swelling and expansion of the wood.

various types and sizes of lumber

Effects of Warm Temperature

Temperature affects wood indirectly. In addition, warm air has a greater capacity to hold moisture. This allows the cells of the shrunken wood to readily absorb moisture, leading to the expansion of the wood. 

Therefore, wood expands cause of warmer temperatures and humid conditions, while high temperatures with low moisture levels can cause it to contract and lose moisture content just as rapidly.

Effects of Cold Temperature

In cold months or winter, wood may experience expansion and contraction. In cold and dry conditions, the air has a low moisture content, causing the wood to release some of its moisture to maintain its equilibrium moisture content. 

In contrast, during a cold temperature with wet air, wood tends to absorb excess moisture, leading to wood expanding, swelling, and warping. 

How to Deal with Wood Shrinkage & Expansion

Sealing Wood

Applying a sealant to wood can help prevent its expansion. Polyurethane and epoxy resin [1] can serve as effective sealers, and applying multiple coats seals the wood airtight, preventing moisture from being absorbed from the external environment, thus inhibiting expansion.


Using Plywood as an Alternative

Plywood is significantly more resistant to dimensional changes than solid genuine wood. 

Therefore, it can be a suitable substitute for solid wood in critical areas like windows, certain furniture components, and doors that are more vulnerable to changes in dimensions caused by humidity.

Selecting Suitable Hardwood

To ensure the stability of your wooden project, it is crucial to use high-quality hardwood that is suitable for the intended purpose. 

This type of wood is typically dense and has a high resistance to moisture loss or absorption, which is essential in maintaining its dimensional stability despite changes in weather conditions.

Seasoning Your Wood

Newly-cut wood and some lumberyard wood may not be dry enough for wood furniture making. Thus, allow the wood to acclimatize to the environment before use, which may take months or years. 

drying wood

Before use, check the moisture levels with a meter to prevent the wood from warping, twisting, or cracking caused by excessive moisture. To check, here’s a list of the lumber yards near you

Disassembling Your Furniture

An infrequent but not unfamiliar practice involves taking apart costly wood furniture at various times of the year. When the weather is suitable, the wood furniture can be reassembled. 

In addition, make sure to keep the wood furniture components in a location equipped with temperature and moisture regulation. Or an area where its own humidity levels can be controlled.

Storing Outdoor Furniture Inside During Cold Weather

Even though outdoor wood furniture is created to endure various elements, it might not do well when subjected to freezing temperatures or extreme cold during the prolonged winter season. 

rubber wood furniture

Likewise, in areas that experience heavy rainfall during specific months of the year, in either scenario, it is advisable to relocate such wood furniture indoors during these times.

Does Sealing Wood Prevent Expansion? Should You Seal or Not?

Using a sealer on wood can prevent it from expanding by serving as a protective layer that separates the wood from the surrounding environment. Which lessens the worry of leaving wood furniture outside.

However, it may not be advantageous to prevent the wood from moving because it naturally adapts to its humidity levels as it is hygroscopic.  

Furthermore, when the wood is sealed with epoxy resin or other wood sealant, it loses the ability to adjust its humidity level, which could result in stress accumulation and deformation, despite not expanding or contracting. Thus, I do not suggest sealing the wood. 

Multiple Urethane Layers

To effectively seal wood, multiple coatings of urethane-based epoxy must be applied to its surface. 

However, it’s essential to exercise caution during this process, as excessive layering can lead to the wood becoming thicker than required, potentially affecting its functionality and appearance.

sealing wood after staining

Temporary Solution

It’s important to recognize that sealing wood to prevent moisture penetration is a temporary solution. Over time, the sealed surface can become abraded or scratched, compromising its effectiveness. 

Consequently, it may be necessary to apply additional layers of waterproofing to maintain the integrity of the seal and continue protecting the wood.

You’ll Also Like:


It’s accurate to acknowledge that wood does expand in cold weather, but it’s essential to recognize that fluctuations in temperature and humidity can cause wood to contract as well. These changes may result in damage or warping of wooden items.

To mitigate these potential issues, it’s crucial to comprehend how wood responds to diverse environmental conditions and to implement necessary precautions. These measures may include storing wood indoors or utilizing sealants to protect it. 

By taking these steps, you can effectively preserve the longevity and appearance of your wood furniture, wooden doors, and other wooden possessions.

robert headshot

Robert Johnson is a passionate furniture maker & carpenter, sought after for his knowledge on the craft.
You’ve probably seen his down-to-earth wisdom in USA Today, Bobvila, Family Handyman, and The Spruce, where he has shared commentary and guidance on various woodworking topics.

Robert is the brain behind Sawinery, where he aims to share tips, tricks, and a passion for all things carpentry.

Leave a Reply

Your email address will not be published. Required fields are marked *

Related Articles
Join our community on facebook and get 3 woodworking plans for free!