Garden room doors that stick, and what the building is telling you

Seasonal swelling or actual movement

Timber doors take on and give up moisture. A door that binds slightly in wet weather and frees up again in a dry spell is behaving normally, and the answer is a small adjustment or an easing rather than an investigation.

Movement is different. It does not reverse. The door catches in the same place regardless of weather, and the gap around the door is visibly wider at one end than the other. That is the frame being pushed out of square by something below or beside it.

Read the gap, not the door

Close the door and look at the shadow line all the way round. A parallel gap means the door has swollen or the hinges have dropped. A tapering gap, wide at one corner and tight at the diagonal opposite, means the opening itself has racked.

Then check the same thing elsewhere in the building. If a window on the same wall has also gone out of square, or an internal joint has opened, it is a structural question rather than a joinery one.

Parallel gap and stiff in damp weather: timber movement or hinge wear · Tapering gap that gets worse: the opening is racking · Cladding joints opening at one corner: settlement on that corner · A floor that has become springy or dips underfoot: support below has moved or decayed · A visible lean when checked against a fence or wall line: base failure

Why one corner drops

Settlement almost always shows at one corner because that is where the ground has given way. Common reasons are a pad that never reached bearing ground, fill placed without proper compaction, ground that has been repeatedly soaked by roof water discharging at the base, or decayed material buried under the footprint that has broken down over time.

The tree question comes up often. Roots can affect ground moisture close to a building, and removing a large tree changes the ground too. Both are worth mentioning to anyone assessing movement, because they change what the likely cause is.

Rot at the base of a timber structure

The other cause of a dropping corner is not the ground at all but the timber sitting on it. If the floor structure or the bottom of a frame has been in contact with wet ground or has had soil banked against the cladding, decay follows. It softens quietly and shows up as a soft floor or a settling corner long before anything is visible outside.

Probing the base timbers and looking at the ground level around the building settles this quickly. The remedy is to remove the decayed sections, correct whatever kept them wet and reinstate with proper separation from the ground.

What a proper repair looks like

The sequence is always the same. Establish and correct the cause, allow the building to be supported correctly again, then adjust or refit the joinery to the corrected opening. Doing the joinery first means doing it twice.

Where a base is at fault, the corner is supported and the failed bearing replaced or extended down to firm ground. Where water was the cause, drainage and ground levels change as part of the same job, otherwise the repair is on a countdown.

When to act rather than live with it

A door that is slightly stiff is a maintenance item. Take it seriously when the gap is visibly tapering and getting worse, when glazing units start to crack without impact, when a floor gives underfoot, or when a lock no longer engages so the building cannot be secured.

Those are signs of continuing movement, and the earlier the cause is dealt with the less of the structure is involved in putting it right.

Frequently asked questions

Can I just plane the door down?

It works until the opening moves further, and then the door no longer fits or seals. It is reasonable for seasonal swelling, not for a frame going out of square.

Is a small crack in the corner of the cladding serious?

Not necessarily. What matters is whether it is stable or growing. Mark the ends and check again after a few weeks of weather.

Why does the floor feel bouncy in one place?

Either the support below has moved, or a timber has softened. Both need looking at from underneath rather than from the surface.

Could new drainage or landscaping nearby have caused it?

It can. Anything that changes how wet the ground stays under and around the building can change how that ground behaves.

Does movement mean the building has to come down?

Rarely. Most cases are a localised base or timber repair once the cause is identified and corrected.