Fix a Sagging Door Hinge with a Longer Screw

A door that scrapes the carpet, fails to latch, or swings open on its own is one of those small household frustrations that gets worse the longer it's ignored. In most Australian homes, the culprit is a tired hinge held in place by a screw that's lost its bite, and the fix is usually quicker than you'd expect. Swapping in a longer screw that reaches past the soft jamb and into the structural framing is a small repair with a big payoff in how the door feels day to day.

The reason this repair keeps coming up in forums from Townsville to Launceston is that door jambs are surprisingly shallow. The hinge screws that come with most doors are only long enough to anchor into the jamb itself, which is usually around 30 mm of dressed pine or meranti. Once those short screws work loose through repeated use, seasonal movement, or a slightly racking frame, the hinge drops and the whole door follows it. Longer screws reach into the framing behind the jamb, giving the hinge something solid to hang from.

Why Doors Sag in Australian Homes

A few local conditions make sagging hinges more common here than in some other places. Many newer homes in growth corridors around Melbourne, Perth, and Western Sydney are built on reactive clay soils that expand and contract with rainfall cycles. That movement puts subtle twist on door frames every time the ground swells and shrinks, working screws loose a fraction of a millimetre at a time.

Humidity plays its part too. Coastal suburbs in Queensland, on the Mid North Coast of NSW, and around Mandurah in WA see large seasonal swings in moisture content, and hollow core doors — the standard fitment in most Aussie post-2000 homes — flex more than solid timber ones. The hinge side takes the strain and the short OEM screws lose their grip long before the door itself shows any sign of wear.

Where foundation movement is the underlying cause rather than the hinges themselves, the door will keep dropping even after fresh screws are fitted. Homes on reactive clay or near large trees shift slowly enough that the symptom looks like a hardware problem at first, so learning the signs of slab movement early saves a lot of wasted effort on repairs that don't hold.

Tools and Materials You'll Need

A quick trip to Bunnings will cover almost everything on this list. You'll want a pack of 30 mm and 40 mm wood screws that match the gauge of your existing hinge screws — most internal doors in Australia use 8-gauge (about 4 mm) hinge screws, so look for galvanised or zinc-plated wood screws in that diameter. Pick up at least four of the longer length in case you need to repeat the fix on another hinge.

Tools are basic: a cordless drill with a Phillips head bit, a sharp 2.5 mm or 3 mm pilot drill bit, a sharpie, a small chisel or oscillating multitool if the screw holes need clearing, and a driver bit with a magnetic collar so the screws don't drop into the door cavity mid-repair. A wood block and hammer can help tap the door into alignment once the new screws are partly home.

Preparing the Door and Frame

Before you start drilling, support the door so its weight isn't hanging off the hinge you're working on. Wedge a piece of folded cardboard under the door or rest it on a stack of old paperback books at the right height; you want the door to sit roughly where it should be when closed, so you can check alignment as you go.

Mark the centre points of the existing screw holes on the jamb side with a sharpie once the door is supported. If the holes are stripped and slightly enlarged, that's fine — the longer screws will bypass the damaged wood entirely and bite into fresh framing. Wipe any dust or old paint flakes from around the hinge leaf so you can see what you're doing, and clear the screw heads of any paint buildup with the tip of a utility knife so the driver bit grips properly.

Replacing the Short Screws with Longer Screws

Work on one hinge at a time, never fully removing all three screws from a single hinge at once. Start with the top hinge, which carries most of the door's weight, and back out the top screw with your drill on a low torque setting. If the screw feels gritty or the head strips, stop and use a manual screwdriver instead — forcing a stripped screw often tears out more wood than it leaves behind.

Drill a shallow pilot hole at the same angle as the original screw shaft, going in about 25 mm with the appropriate sized bit. Under-drilling is the safer mistake here because hardwood framing behind the jamb can split if you force a screw without a pilot, and a split stud is a much bigger problem than a sagging door. Drive in your new 40 mm screw slowly, feeling for the moment the threads bite into the framing stud behind the jamb — you'll feel a small, satisfying change in resistance.

Repeat the process on each screw location in turn, then close the door and check the fit before moving to the next hinge. Address the middle hinge next if the door still drops, and only then re-set the bottom hinge. Once all three top and middle hinges are carrying into the framing rather than just the jamb, most doors lift back into a clean, even gap within a couple of millimetres of where they should be.

When a Longer Screw Isn't Enough

Sometimes a door keeps sagging even after the screws are anchored deep, and that usually points to one of three underlying issues. The hinge itself can be worn — brass hinges in older Queenslander-style homes sometimes stretch over decades, and no amount of longer screws will hold a hinge that's bent out of plane. In that case, replace the whole hinge with a new stainless or zinc pair from your hardware supplier, using the longer screws as you go.

The frame itself can also be the problem. If you can see daylight along one edge of the closed door or the gap between door and jamb widens noticeably from top to bottom, the house may be settling unevenly. Tree roots can change moisture levels under the slab faster than the surrounding clay, and if you've got a big gum or jacaranda within a few metres of the house, it's worth checking whether that tree is part of the problem before going over the same hinge replacement a second time.

Finally, check the hinge mortises themselves. If a hinge is sitting too deep in its cut-out, no screw upgrade will pull it flush. Shimming the hinge leaf with a thin cardboard gasket or packing it out with a second layer of kraft paper can restore the geometry and let the door close properly again.

Keeping the Door Square Over Time

Once the door is hanging true, a little maintenance goes a long way toward keeping it that way. Avoid hanging heavy items like wet coats or school bags on the door itself, as the leverage slowly bends the hinges and drags the screws back out. If the house has ceiling fans nearby, make sure the door sits a few centimetres clear of any doorstop trim so the fan's vibration doesn't transfer into the frame.

Lubricating the hinge pins with a drop of sewing machine oil or a spritz of dry PTFE lubricant once a year keeps the pins free of rust and stops that midnight squeak that always seems to come from the bathroom door. Tighten the visible screw heads with a hand screwdriver during the same seasonal tidy-up — they always loosen just enough to need a nudge, and catching them early prevents the longer screws from being tested before they need to be.

If the door still drags after the screw upgrade, run a strip of painter's tape along the floor where the door rubs and close it gently — the scuff mark on the tape tells you exactly where to sand or plane by less than a millimetre to bring the door back into a clean, even gap.