How do I fix a fence panel?

How to replace a broken fence panel or repair a leaning post, and how to work out which is actually the problem.

Difficulty: intermediate
Time: 2 hr
Read: 3 min
Safety: caution

Short answer

Check the posts before the panels — a leaning fence is nearly always a rotted or loose post rather than a failed panel. Panels slide out of concrete posts easily; timber posts need the panel unscrewed. A rotten post at ground level needs replacing or supporting with a concrete repair spur.

Fences fail at the posts, almost always at ground level where timber meets soil and stays wet. Replacing a panel on a rotten post is wasted work — it'll blow out again in the next storm. Checking the post first is what determines whether this is an hour's job or an afternoon's.

Safety

Check for buried services before digging any post hole. Fence panels are large and act as sails — never attempt to remove or fit one alone in wind. Concrete posts and gravel boards are extremely heavy; get help lifting them. If the fence is on a boundary, establish who owns it before altering it.

What you'll need

Replacement panel or post
Screwdriver or drill
Spirit level
Spade
Postcrete or concrete repair spur (optional)
Gloves

Step by step

Establish whether the fence is yours before doing anything.Check the deeds or the plan. Altering a neighbour's fence without agreement causes disputes.
Test each post by pushing it firmly.Movement at the base means the post has rotted or the concrete has failed. That's the actual problem, not the panel.
Check the post at ground level, where rot starts.Push a screwdriver into the timber just above and below soil level. If it sinks in, the post is gone.
For a sound post and a broken panel, remove the damaged panel.Concrete posts: the panel lifts straight up out of the slot. Timber posts: unscrew the fixing brackets or nails.
Fit the replacement panel, checking it sits level.Measure the gap before buying — panel sizes vary, and 'standard' covers several dimensions.
For a rotten timber post, either replace it or fit a concrete repair spur.A repair spur bolts to the sound upper part of the post and is concreted into the ground alongside — far less work than a full replacement.
For a full post replacement, dig out the old concrete, set the new post plumb and use a fast-setting post mix.Post depth should be about a quarter to a third of the visible height. Brace it while the concrete sets.
Fit gravel boards at the base so panels don't sit on soil.This is what prevents the next failure — it keeps the panel timber out of permanent ground contact.

Tips

Concrete posts with concrete gravel boards essentially eliminate the rot problem, and panels then slot in and out without tools.
Fix a repair spur to the good part of the post rather than replacing the whole post, where possible — it's a fraction of the work.
Treat cut ends of timber with preservative. The cut end is the most absorbent part and where rot starts.
Storm damage may be covered by home insurance, though many policies exclude fences. Check before paying for repairs.

Common mistakes

Replacing the panel without checking the post — A rotten post fails again in the next storm, taking the new panel with it.
Setting a post too shallow — A quarter to a third of the visible height needs to be in the ground, or it leans within a year.
Panels sitting directly on soil — Permanent ground contact rots the bottom rail within a few years. Gravel boards prevent it.
Working on a fence in wind — Panels catch wind like sails and are genuinely dangerous to handle in a gust.

Questions people ask

Which fence is mine?

Check the deeds or title plan, which often mark boundary ownership with a 'T' on the owning side. The common assumption that posts face the owner's side is a convention, not a rule.

Can I repair a rotten post without replacing it?

Often, yes — a concrete repair spur bolts to the sound upper section and is concreted in alongside. It's much less work than digging out the old post and its concrete.