7 May 2026
Why some doors start to stick as the weather warms
Find out whether a sticking door is ordinary timber swelling or a sign the ground beneath your home is moving. Describe what you have noticed and get an answer without paying anything.
Timber swells when the air turns damp and warm
A wooden door sits inside a frame that is also made of wood. Both pieces absorb moisture from the air around them. In early May, Kent mornings can still be cool while afternoons turn mild, so humidity rises quickly.
When the timber takes on moisture it expands across the grain. The door grows slightly wider and thicker. If the gap between the edge of the door and the frame was already tight, that small expansion is enough to make the two surfaces rub together. You feel it most at the latch side or along the top edge.
This kind of sticking usually eases once drier weather returns. It affects internal doors just as much as external ones because indoor humidity follows the same pattern. A carpenter might plane a millimetre off the edge, but often no work is needed. The timber simply responds to the season.
Clay shrinks and pulls the frame out of square
Many homes in Kent sit on Weald Clay or Gault Clay. These soils hold water through winter and lose it steadily once temperatures climb. By early May the surface layers are already drying out.
As clay loses moisture it shrinks. The ground beneath the foundations drops unevenly, so one corner of the house settles a fraction lower than the rest. The door frame, which was built square, twists with the wall around it. The door itself has not changed size, but the opening it hangs in has altered shape.
A door that sticks because of ground movement behaves differently from one affected by swollen timber. It catches in the same place regardless of the weather. You might notice the gap at the top is wider on one side, or the latch no longer lines up with the strike plate. Paint may crack where the architrave meets the plaster.
How to tell seasonal swelling from structural shift
Run your hand along the edge that catches. If the wood feels damp or the paint seems soft, moisture is likely the cause. Try the door at different times of day. Timber swelling changes with temperature and ventilation, so a door that sticks at noon might swing freely by evening.
Ground movement leaves other signs. Look at the walls near the door for fresh cracks, particularly thin diagonal lines running from the corners of the frame. Check whether skirting boards have pulled away from the wall. Open windows in the same room and see if they jam too. When several openings in one area start misbehaving at once, the frame holding them is probably shifting.
If you suspect the soil is moving rather than the wood expanding, a structural movement survey will show where the distortion starts and how far it reaches.
What happens next if the ground is moving
A specialist firm carries out a structural movement survey to measure the distortion. They record crack widths, check levels across floors and look at the soil type beneath the footings. On clay sites they may recommend crack monitoring over several months to see whether the movement is seasonal or continuous.
Drainage leaks can accelerate clay shrinkage by washing fine particles away, so a drainage CCTV survey sometimes forms part of the investigation. Once the cause is clear, the specialist firm decides whether the home needs underpinning, resin injection or screw piling to stabilise the foundations.
None of this work begins until the measurements confirm it is necessary. Many homes settle slightly each spring and recover in autumn without any intervention. The readings determine whether the sticking door is a passing nuisance or proof that the ground underneath needs support.
Ask about a sticking door in your home
Send details of what you have noticed. The information goes to a specialist firm who will say whether the signs point to timber swelling or ground movement. There is no charge for this first response.
- No fee for advice
- No obligation to proceed
- Local specialists only