DOORS & JOINERY

Fix a sagging door

Diagnose why your door sags, tighten or repack the hinges, and re-fix the frame safely into whatever's behind it.

AB-01Work out why the door is saggingOpen and close the door slowly and watch exactly where it rubs - top corner, latch edge, or along the bottom. Push and pull the door while watching each hinge; if a screw head moves in or out, that hinge is your problem. Look at the gap between frame and wall too - if the whole frame has pulled away, tightening hinges alone won't fix it.
AB-02Tighten every hinge screwUse a manual screwdriver rather than a drill, so you can feel if a screw is turning without gripping - that's a stripped hole, covered next. Tighten top, middle and bottom hinges on both the door leaf and the frame side. Keep the same number and type of screws you removed.
RULES
1 each · Manual screwdriver
KNOW THE RULES

If this is a fire door - a flat entrance door is the common example - it depends on approved hinges and fixings to work properly. Don't swap hinge type or screw count without checking; this matters under Building Regulations Part B.

AB-03Fix a screw that spins without tighteningA spinning screw means the hole has worn oversized in the timber. Take the screw out, dip 2-3 cocktail sticks or a broken matchstick in wood glue, and pack the hole tight. Leave the glue for at least 30 minutes, then drive the original screw back in - it will bite into fresh wood.
1 each · Wood glue (small bottle)
1 pack · Cocktail sticks
AB-04Work out what's behind the frame before you drill deeperRun a stud detector or a strong magnet along the wall next to the frame. A steady line of hits every 400-600mm usually means timber studs; a magnet catching screw heads in a thin, regular metal track means metal studs. Drill a 2mm pilot hole in an unseen spot and check the dust: pale wood dust means timber, fine grey swarf means metal track, and dense grey dust with no give means solid brick or block. Cables and pipes can run almost anywhere near a frame, especially close to light switches - use a cable and pipe detector but still treat the wall as live until proven otherwise. Find your stopcock (usually under the kitchen sink) and check it turns before you start, and isolate the circuit at the consumer unit if you're in any doubt.
1 each · Stud detector
1 each · Cable and pipe detector
AB-05Choose the right fixing for what you foundInto a timber stud or solid timber lining, use a 4x75mm wood screw driven into the centre of the timber. Into a metal stud, a wood screw strips straight through 0.5mm steel - use a self-drilling metal-stud screw or a toggle-type hollow-wall fixing rated for the pull on a door frame. Into solid brick or block, drill a 6mm hole 45mm deep, fit a red wall plug, and use a 4x60mm screw. Behind dot-and-dab plasterboard, use a fixing long enough to pass through the board and dab and bite into the masonry behind, typically 75-90mm; through lath and plaster, drill gently to avoid cracking the lath, then fix into whatever's behind it using the same rule.
8 each · Wood screws 4x75mm
8 each · Metal-stud self-drilling screws
8 each · Red wall plugs
4 each · Long fixings for dot-and-dab (75-90mm)
AB-06Re-fix the loose frameHold the frame square in the opening using a spirit level on the face and a straightedge to check it hasn't twisted. Drive the correct fixing through the frame at the point closest to where it has pulled away, then check the door swing before adding more screws. Correct the frame's position as you go rather than fixing everything at once.
1 each · Spirit level
AB-07Pack out an uneven hingeIf one hinge sits too deep in its recess, the door will still bind even after refixing. Cut a piece of thin cardboard or a hinge shim to match the hinge leaf, slot it behind the leaf, and re-screw. This brings that side of the door forward slightly and closes the gap.
2 each · Hinge shims or cardboard offcut
AB-08Test the door and trim if it still catchesOpen and close the door fully several times, checking it swings freely and the latch meets the keep without forcing. Check the gap around the frame - roughly 2-4mm all round is normal. If it still catches, find the high spot on the door edge and plane or sand it lightly rather than adding more packing.
1 sheet · Sandpaper (medium grit)
AB-09Tidy upVacuum up dust, swarf or shavings from the floor and frame ledge. Wipe down the door and frame, and bin any offcuts or old screws rather than leaving them lying around. Store spare fixings in a labelled bag for next time.

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