How to Fix a Sagging Timber Gate
Updated: Sep 27
A timber gate that has dropped is one of the most common jobs we get called out for, and it is almost always one of three things: the gate post has moved, the gate frame has racked out of square, or the hinges and hardware were never up to the weight. Work out which one it is before you buy anything, because the fix for each is different and the wrong fix lasts about a season.
Find out what is actually failing
Open the gate to about halfway and look at it from the side, then lift the latch edge with your hand.
If the whole gate and post lean together and the post feels loose at the ground, the footing has failed. Fixing the gate itself will not help.
If the post is plumb and solid but the gate hangs out of square, with a wider gap at the top of the latch edge than the bottom, the frame has racked.
If the post is solid and the frame is square but the gate has dropped as a unit, look at the hinges. Elongated screw holes, bent leaves or a pin worn oval all point the same way.
If the gate binds only in wet weather, that is timber movement, and the answer is usually clearance and a finish rather than structural work.
A quick check that saves arguments: hold a spirit level on the hinge post, then measure the diagonals of the gate frame corner to corner. If the two diagonals differ, the frame is out of square regardless of what the post is doing.
Fixing a leaning gate post
A gate post carries a cantilevered load that swings every time someone walks through, so it works far harder than a fence post. That is why gate posts want to be bigger, deeper and better concreted than the rest of the run, and why an undersized one eventually leans toward the opening.
Depth and diameter both matter. A gate post generally goes deeper than the line posts either side of it and gets a proper concrete footing, not a dry mix tipped in around it.
On reactive clay through the Hills District and parts of south-western Sydney the ground moves seasonally, so the footing needs to get below the layer that dries out and swells.
Close to a sandstone shelf, which is common through the Sutherland Shire and the North Shore, drilling into rock gives an excellent footing but takes the right gear.
On a slope the hole is measured from the low side, which is the same principle that governs fencing on uneven ground. Our guide to a Colorbond fence on a sloping block explains why.
Water pooling at the base of a timber post will eventually rot it at ground line, and a post that is sound above ground can be gone at the collar. Push a screwdriver into the timber right at soil level before deciding to reuse it.
If the post is rotted at ground line, replacing it is the only real fix. Raking it back upright and re-concreting a compromised post buys a year at best.
Fixing a racked frame
Timber frames rack because the gate is effectively a rectangle hanging off two points. Without something resisting that movement, gravity turns the rectangle into a parallelogram.
A diagonal timber brace is the traditional answer. It has to run from the bottom of the hinge side up to the top of the latch side, so it works in compression. Fitted the other way around it does very little.
An adjustable anti-sag kit, the cable and turnbuckle type, runs the opposite way because it works in tension: top of the hinge side down to the bottom of the latch side. Getting this back to front is the single most common mistake on a do-it-yourself repair.
Fixings matter as much as bracing. Screws or bolts through the frame corners hold far better than nails, which work loose with every swing.
On a wide or heavy gate, a ledged and braced frame with a decent rail section will always outperform a light frame with a brace added later.
A racked frame can usually be pulled back square and then braced, but if the joints have opened up and the timber is soft at the corners, you are bracing something that has already given up.
Hinges and hardware for a heavy gate
Hardware is where money gets saved and then spent twice. A solid hardwood gate, especially a double driveway gate, weighs a lot more than the light garden gate the hinges in the hardware aisle were designed for.
Match the hinge to the actual weight and width of the gate, not to what looks about right. Three hinges on a tall gate spread the load better than two.
Fix into solid timber. Hinge screws biting only into a thin cover board or into end grain will pull out.
Near the coast, through the Eastern Suburbs, Northern Beaches and the beachside parts of the Shire, salt will find cheap hardware quickly. Corrosion-resistant fittings are worth the difference, which is the same reasoning behind our post on the best fence for coastal Sydney homes.
Adjustable hinges make later fine-tuning simple, which is genuinely useful on a timber gate that will move a little with the seasons.
Clearance, latches and the gap at the bottom
Once the gate is square and hanging properly, the gap is what makes it feel right. Too tight and it binds in humid weather, too loose and the latch will not engage cleanly. Aim for a consistent gap down the latch side and enough clearance at the bottom that the gate is not dragging on a paver or a rising path.
If the gate is a side access gate, check it still clears what it needs to clear: a wheelie bin, a mower, a wheelbarrow. We cover sizing in more detail on our gates guide.
When it is cheaper to rebuild the gate
Repairing is the right call when the frame is sound and the problem is a post, a brace or hardware. Rebuilding usually wins when:
The frame joints have opened up and the timber is soft at the corners or at the bottom rail.
The gate has already been braced once and dropped again.
The palings are splitting and cupping badly enough that they need replacing anyway.
The fence either side is also near the end of its life, in which case doing the lot together makes more sense. Our post on when to replace a fence walks through that decision.
Keeping it from happening again
Timber gates last well when the water is kept out of the end grain and the hardware is checked occasionally. Re-coat the gate when the finish starts to go chalky, pay particular attention to the cut ends and the bottom rail, keep soil and mulch away from the base of the posts, and give the hinge screws and any tension cable a check once a year. There is more in our fence maintenance tips post, and more on timber generally in our guide to timber paling fences.
Common questions
Which way should an anti-sag cable go?
From the top corner on the hinge side down to the bottom corner on the latch side. It works in tension, pulling the dropped corner back up. A timber brace does the opposite job and runs the other way, from the bottom of the hinge side to the top of the latch side, because it works in compression.
Can I just re-concrete the existing gate post?
Sometimes, if the post is sound timber and the problem is purely the footing. Check the post at ground line first with a screwdriver. If it gives, the post is the problem and re-concreting it is money spent on a post that is already failing.
Why does my gate only stick in summer?
Timber takes up moisture and expands, and a gate fitted with a very tight gap will bind once the humidity climbs. Planing a little clearance on the latch edge and sealing the cut face usually settles it without touching the frame or hinges.
Should a gate post be bigger than the fence posts?
Generally yes. A gate post carries a swinging load the line posts never see, so it is normal for it to be a larger section, set deeper, with a more substantial footing. On a double driveway gate both posts carry that load.
Is a sagging shared gate my responsibility or my neighbour's?
It depends on where the gate sits and what it serves. Shared boundary structures in NSW are covered by dividing fence rules rather than by whoever complains loudest, and our post on who pays for a dividing fence in NSW explains the usual process. For anything contested, NSW Fair Trading is the right place to check your position.
Get it looked at properly
We repair and rebuild timber gates across Sydney, and we would rather tell you the post needs replacing than hang a new gate on a footing that is on the way out. Have a look at our timber gates and gate installation pages, or the full range of our fencing services.
If your gate is dropping, get in touch for a quote and we will tell you whether it is a hardware job, a post job or a new gate. If the gate is past repairing, our guide to timber side gates covers getting the replacement right.
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