How to stop doors swelling in summer

Do you have an internal door that gets stuck all the time? If so, you’re far from alone – it’s a very common problem. Maybe your door catches at the top, or sticks in the corner. Perhaps the problem is a sticking door latch. The good news is that whatever the issue, it’s usually quite easy to prevent doors from sticking or jamming, or to fix a sticking door that’s already giving you problems.

Wooden doors are more prone to sticking than doors made from uPVC. This is because wood is a natural material which reacts to changes in temperature and humidity. Installing a dehumidifier can help reduce humidity, but homes are designed to be lived in and this means that there will always be changing temperatures, and the amount of moisture in the air will always be in a state of flux.

Why do internal doors stick?

Doors stick for many different reasons.

• The wood has swollen.
• The frame has swollen or warped.
• The door is not hanging correctly in the frame – either because the frame has shifted, or because the hinges are warped or damaged.

Humidity is any wooden door’s worst enemy. It causes swelling and warping of doors, frames, furniture, and even the wooden frames in your roof. If the humidity level’s stable, then eventually things should balance out, but if it is constantly changing it presents its own problems.

Foundation problems

Shifting foundations are a common problem with newer homes. Over time the foundations ‘settle’, causing walls to warp, and mean that your door frame is no longer plum. Usually, houses are built to cope with a certain level of shift, but if the shift is significant it will cause issues with door alignment and consequently doors that stick. You might even get cracks in the walls.

In addition, poorly made hinges could sag or warp over time. It’s not uncommon for builders to skimp on fittings, and do things like hanging a heavy door with just two hinges instead of three. This could lead to those hinges sagging, and a door that sticks.

Why do wooden doors swell?

Wooden doors swell because they absorb moisture from the air. It is not uncommon for the humidity in a home to be around 50%, and if your door was made and stored in a much drier environment, then it is going to absorb a lot of that moisture when you install it.

Wood expands in warm temperatures, and contracts in cool temperatures. This causes issues with the way the door fits in the opening. If you live in an area that is humid year-round, the door will swell. Even in ‘dry’ areas, if you tend to use the shower with the doors and windows shut, your bathroom could end up with a sticking door from the extra humidity in that room.

How to fix a door that sticks

There are a few approaches you can take to fixing a stuck interior door.  Before you start fixing a sticking door, it’s important that you figure out what’s causing the door to stick.

In some cases, the cause of the sticking door is simple – a build-up of dirt and grime. Simply cleaning that grime off could fix the problem. This could be in the frame of the door, or you might have a sticking door latch that needs cleaning.

If simply cleaning the door doesn’t fix the problem, the next step is to figure out where the door is sticking. Run a piece of paper around the top, bottom and latch side of the door – the point where the paper stops and gets stuck is the area that is sticking.

Open and close the hinges. If the hinges squeak, this is a sign that they probably need to be oiled. Before you do this, check that the door is plumb – if it is sticking towards the top of the door and the hinges are creaking, then the hinges could be sagging, and need to be tightened or adjusted.

If the door is sticking in several places, it could be swollen because of the humidity. This is likely to be the problem if your door sticks in summer, but is fine during the winter. If you have one, try running your air conditioner to get rid of the moisture in the air. Running a dehumidifier can help, too.

In fact, a portable dehumidifier can get rid of several litres of water per day, and will help the door return to its original size. You may want to paint or seal the door once it is the correct size, to protect it from the effects of the humidity.

Trimming a door down to size

If the above options fail, you may need to trim the door down to size. Once you do this, you cannot undo it, so make sure that humidity is not the issue, and that the hinges are in good condition before you start work.

1. Identify the area where the door is sticking, and mark that spot on the door with a pencil or some chalk. There is no need to remove wood from anywhere else on the door; you simply want to clean up the area where the door is sticking.
2. Remove the door from the hinges, and use a sharp door planer to trim a small amount of wood. If you are not confident in how to do this, and you are looking to remove only a small amount of wood from the door, then you might want to use a palm sander instead.
3. Work slowly and carefully. Remove a small amount of wood and then test the fit of the door. If necessary, go back and remove more. Always err on the side of removing too little wood – because if you remove too much, you cannot put the wood back!

Once you have finished, repaint the section of the door that you have trimmed, and allow the paint to dry. The door should now move freely and look as good as new.

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