GuideFences & Gates
How to Fix a Sagging Wooden Garden Gate
A gate that drags on the ground or will not latch is one of the most common garden annoyances. The cause is usually one of three things: loose hinges, a gate frame that has racked out of square, or a leaning post. This guide helps you find which one and fix it.
What you will build
You will diagnose the sag, then fix it in the right place. Loose hinges are tightened with longer screws or through-bolts. A racked gate is squared up and given a diagonal brace or an anti-sag cable. A leaning post is a bigger job, covered at the end.
The key fact about bracing: a wooden brace works in compression, so it must run from the bottom corner on the hinge side up to the top corner on the latch side. A steel cable or turnbuckle works in tension, so it runs the opposite way, from the top hinge corner down to the bottom latch corner.
Real-world examples
Photos of similar builds by other people, shared under open licenses. They show the idea in practice; the details differ from this guide.
Materials
- Exterior screws longer than the existing hinge screws, or carriage bolts with nuts and washers
- A board for a diagonal brace, the same thickness as the existing frame rails
- Or: an anti-sag gate kit (cable and turnbuckle)
- Wood glue rated for exterior use
- Wood shims or a car jack and offcuts to lift the gate
Tools
- Drill/driver and bits
- Spirit level
- Square
- Saw
- Clamps
- Spanner for bolts
- Safety glasses and gloves
Step by step
1Find out what is sagging
Close the gate and hold a level against the hinge post. If the post leans, the post is the problem. If the post is plumb, check the hinges by lifting the latch end of the gate: if the hinges move or the screws pull out, they are loose. If the hinges are tight but the gate's corners are no longer square, the frame has racked.
2Tighten or reset the hinges
Prop the gate up level with shims or offcuts underneath. Replace stripped hinge screws with longer ones that bite into fresh wood, or through-bolt the hinges with carriage bolts. Fill old, oversized holes with glued wooden plugs before re-drilling.
3Square up a racked gate
Take the gate off its hinges if possible and lay it on a flat surface. Push it back into square, checking with a square or by measuring the diagonals, and hold it there with clamps.
4Fit a diagonal brace
Lay a board across the back of the gate from the bottom hinge-side corner to the top latch-side corner, mark the angled cuts where it meets the rails and cut it to fit tightly. Glue and screw it into the rails and through the boards. Rehang the gate and check that it swings and latches freely.
5Or fit an anti-sag cable
If you cannot fit a wooden brace, install an anti-sag kit: fix the top bracket at the hinge-side top corner and the bottom bracket at the latch-side bottom corner, then tighten the turnbuckle until the gate lifts back into square. Do not overtighten.
6If the post leans
A leaning hinge post usually means the post has rotted at ground level or its footing has moved. Short-term, a diagonal brace from the post to the ground can help. The lasting fix is to reset or replace the post; see our guide to replacing a broken fence post.
Tips for a better result
- A heavy gate needs three hinges, not two; the middle one takes much of the load.
- Leave a gap of about ¼ to ½ in (6–12 mm) at the latch side so the gate does not bind when the wood swells in wet weather.
- A gate stop on the post stops the gate swinging too far and straining the hinges.
- Re-check the screws once a year, especially after a wet winter.
Common mistakes to avoid
- Fitting a wooden brace the wrong way, from the top hinge corner down; it pushes the gate further out of square.
- Putting longer screws back into the same rotten wood instead of moving the hinge or plugging the holes.
- Planing the bottom of the gate so it clears the ground, while ignoring a leaning post.
- Overtightening an anti-sag cable so the gate twists.
Safety
- Support the gate before removing hinges; even small wooden gates are heavy and awkward.
- Wear safety glasses when drilling and cutting, and gloves when handling old, splintered wood.
General guidance only. Follow the instructions for your tools and materials and your local rules, and use a qualified professional for electrical, gas and structural work.
Finishing up
Most sagging gates can be fixed in an afternoon once you know where the problem really is. A tight set of hinges and a correctly placed brace will keep the gate swinging and latching smoothly for years.
About this guide: written by the DIY Outdoor Builds editors from general, widely used building and gardening practice. Text and illustration © DIY Outdoor Builds. Photos are by the people credited under each one, used under their licenses. Found an error? Let us know.
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