Why are the gaps around my door uneven?

The gap around a door is a measuring instrument. It is the cheapest diagnostic you have, and it distinguishes the three faults that all present as 'the door sticks' but have completely different fixes.

What you'll need

• A pound coin or a 2mm packer
• A screwdriver
• A pencil

Step by step

1. Close the door and step back.Look at the whole margin at once rather than at the point that rubs. The rub is the symptom; the shape of the gap is the diagnosis.
2. Check the top gap.It should be an even 2mm the whole way across — about a pound coin. If it is wide at the hinge side and closed at the latch side, the door has tilted away from the top hinge.
3. Check the latch-side gap.Also about 2mm, parallel top to bottom. A wedge shape here is the clearest sign of a dropped door or a moved frame.
4. Check the hinge-side gap.It should be almost nothing at the top and bottom and consistent between. A gap that opens up on the hinge side means the hinge recesses are too shallow or a screw has pulled.
5. Check the bottom.Around 6mm over a hard floor, more over carpet. A bottom gap that changes across the width means the frame is out of square rather than the door.
6. Test the hinges before blaming the door.With the door half open, lift the handle. Any movement at all means loose screws or a worn knuckle, and that alone can close a 2mm gap.
7. Apply the diagonal rule.Rubbing at the top of the latch side is fixed at the top hinge. Rubbing at the bottom of the latch side is fixed at the bottom hinge. Packing a hinge pushes the door away from that hinge.
8. Check the frame with a level.If the frame itself is out of plumb, no hinge adjustment gives you an even gap. That is a frame problem, and the door has to be fitted to the frame as it is.
9. Only then consider planing.Planing is irreversible and removes the paint seal. It is the right answer when the door is genuinely too wide, and the wrong answer when a screw was loose.

Tips

• Mark the rub with chalk on the door edge, close it, and see what transfers to the frame. It pinpoints the contact within a few millimetres.
• Do this check in the season the problem is worst. A door that binds only in a wet August is swelling, not dropping.
• Photograph the closed door before you change anything. It is surprisingly hard to remember what the gap looked like an hour later.

Common mistakes

• Planing the edge that rubs — The rub is usually caused by a tilt originating at a hinge on the opposite side. Plane it and the door fits at that moment, but the moment the hinge is corrected there is a permanent tapered gap.
• Ignoring a gap that only appeared recently — A gap that has changed over months is telling you something is moving — a settling frame, a failing lintel, or a floor deflecting. Adjusting the door hides a symptom worth understanding.

If it doesn't work

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