Does wood expand in winter or summer?

Wood is a porous material. Even when it is used in furniture, or installed throughout a property, it still retains a certain level of moisture content.

As temperature and humidity changes throughout the year, this level of moisture can fluctuate up and down, causing the timber to expand and contract.

In UK properties, wood throughout the home tends to expand in winter and contract in summer. This is mainly due to the weather and poor air circulation in the property.

does wood expand in winter or summer

During winter, humidity inside the home is higher. This is because windows and doors are often shut, and moisture in the air is unable to circulate out. The following factors also contribute to higher levels of moisture:

  • People spend more time at home – As a result moisture in human breath and other bodily functions add significant moisture to the air.

  • Steam from cooking and bathing – This is less likely to be released, as it is cold outside, and windows and doors remain closed more often.

  • Drying clothes indoors – People will often dry clothes indoors adding additional moisture that is also not removed.

In contrast, summer is much warmer. This means windows and doors are left open far more often. People also spend more time outdoors, and clothing can be dried on the line outside.

This means that the level of humidity in the home is much lower in summer. As a result, wood will tend to contract in the warmer months.

Examples of wood expanding in winter

A common example of wood expanding in winter, is when internal doors start to swell and stick. This is a very common problem, which is caused by the door absorbing water, and raising its own moisture content.

This is usually combined with less than perfect fitting. You will generally find that a door will stick in one particular place. This is a sign that the gap around the door isn’t completely even.

The area that is sticking, will have a slightly smaller gap than the rest of the door. To fix this, you can simply plane the part of the door that is sticking. This will even out the gap and it should remain consistent around the door as it gradually expands and contracts throughout the year.

You can learn more about doors swelling in winter here

Another area you may notice problems, is gaps in skirting and architrave. In this case, the problem actually happens the opposite way round. You will notice it in summer when the wood contracts.

When this happens, gaps can form on the scribes and mitres. In winter they could be tight and then in summer a gap could open up, causing cracking in the filler and caulk.

Again, when this causes a noticeable problem, its usually due to poor fitting. If the boards are fitted tight and secure, its less likely they will gap as they contract.

You can learn how to fix cracks and gaps in skirting here.

Ways to reduce wood expanding in winter

As we already mentioned, wood expands due to moisture. This means, to reduce it, you need to reduce the level of moisture in the air. This can be done by improving circulation and extracting moisture in your home. Below you can see examples of ways to do this:

  • Make a conscious effort to open windows and doors more often. This will allow air to circulate and help to remove moisture in the air.

  • Open your windows when cooking and bathing. This might be a little colder, but it will massively reduce moisture added to the air in your home during these tasks. Also, at the same time, try to isolate the moisture by closing doors that lead to other areas of the home.

  • If you need to dry clothes indoors, try to isolate this activity to one room. Also, make sure this room is well ventilated and moist air is able to escape. By having the door closed, you avoid moisture spreading around the home.

  • Have extractor fans installed. This is an extra expense, but it is more than worth it. An extractor fan in your bathroom and kitchen will have a massive impact on removing moisture. It will also let you avoid opening windows as often.

  • Use a dehumidifier. This is a relatively cheap and extremely effective way of removing moisture from a property. You will actually be very surprised how quickly these fill up during winter. You can see a great example of an affordable, good quality dehumidifier, by clicking here.

All of the above will help to reduce moisture and humidity in your home. By doing this, your wooden fixtures, such as doors, skirtings, and architrave, should expand and contract far less as a result of these measures.


As you can see, wood tends to expand during winter in UK homes. This is mainly due to higher levels of moisture during these colder months.

The actions mentioned above, can greatly help to reduce this moisture. In turn, the timber in your house will expand and contract far less.

Not only that, but reducing moisture can be beneficial to health, and it will also reduce condensation, damp, and the mould, that can form as a result.

Obviously, having windows open during winter is not always an option, especially with soaring energy prices. Therefore, an affordable option, such as a dehumidifier can be a great way to extract moisture, whilst also maintaining a comfortable temperature in the home.

Again, you can see a good dehumidifier and read customer reviews, by clicking here.