garden

How to Repair and Re-hang a Sagging Garden Gate

Gabriel

25 Dec 2025 — 3 min read

A sagging garden gate is a common problem that gradually worsens — the gate starts dragging on the ground or the latch no longer aligns, and eventually it stops closing at all. In most cases the gate structure itself is fine and the problem is with the post, the hinges, or the gate frame. This guide covers systematic diagnosis and repair.

Diagnosing the Problem

Open and close the gate slowly, observing where it drags or misaligns:

Dragging at the bottom corner opposite the hinges: The gate has dropped — either the hinges have sagged, the hinge post has leaned, or the gate frame has racked. The most common cause.
Gate won't close (latch side hitting the frame): Post has leaned, or the gate has swollen with moisture.
Gate bangs against the post: Gate has dried out and shrunk, or the latch post has moved outward.
Gate racking (diamond-shaped instead of square): A diagonal brace has failed or was never fitted.

Hinge Problems

Hinges are the most common failure point. Check each hinge individually:

Are the screws tight? Screw holes in softwood enlarge over time. If screws spin in place, remove them, inject wood glue into the holes, and re-drive with longer or slightly thicker screws. Allow the glue to cure before loading the gate.
Are the hinge leaves corroded? Surface rust on steel hinges can be cleaned with a wire brush and treated with rust converter, but hinges that are structurally thinned by corrosion need replacing.
Is the hinge post itself sound? Probe the base of the post at ground level — this is where rot typically starts. If the post is soft when probed with a screwdriver, it needs replacement before any hinge work is worthwhile.

Adjusting the Hinges

Many modern gate hinges are adjustable — they have slotted or eccentric adjustments that allow the gate to be raised, lowered or moved left/right without removing it. A few minutes with a spanner can often resolve a sagging gate on adjustable hinges.

For traditional fixed hinges, to raise a dropped gate:

Open the gate and support it with a prop or wedge at the correct height.
Pack behind the lower hinge with a thin steel shim or folded aluminium strip — this tips the hinge angle and raises the free corner of the gate.
Alternatively, fit the lower hinge slightly higher on the gate (requiring new screw holes) which has the same effect.

Fitting a Diagonal Anti-Sag Brace

If the gate frame has racked (gone out of square), fit a diagonal wire-tensioning brace or a timber diagonal brace. The brace runs from the bottom hinge corner to the top latch corner — this is the key direction to resist the gate's tendency to sag under gravity.

For timber frames, fit a 75 × 25mm timber diagonal, screwed and bolted into the horizontal rails. For a lightweight tubular frame, use a stainless steel turnbuckle (bottle screw) with wire cables — tension until the gate is square, then check that the diagonals are equal before fixing.

Post Replacement

A rotted or leaning post must be replaced — no amount of hinge adjustment compensates for a failing post. For a timber post:

Remove the gate from the old post.
Dig out around the base of the existing post — or, for fence posts, cut the old post at ground level and leave the concrete-encased root (fit the new post alongside).
Dig a new hole to 750mm depth for a 1.8m post (deeper in unstable or frost-prone soils).
Set the new post in concrete (Postcrete or a 1:2:4 mix), checking for vertical on two faces with a spirit level.
Allow concrete to cure for 48 hours before rehinging the gate.

Use pressure-treated (UC4 grade) timber for all in-ground posts. Even treated timber will eventually rot in constant soil contact, but the treatment extends service life to 15–20 years. Alternatively, use galvanised steel post holders (AKA post spiked in UK) that keep the timber above ground — more durable but the spike holder itself must be correctly driven.