Wobbly garden fence panel? Here's what's usually wrong

The first decent breeze of May arrives and so does the phone call. "Martin, the fence has come loose again." I've lost count of how many fences I've fettled around Cirencester and the villages. It's usually the same three culprits.

Check the post, not the panel

Grab the post, not the panel, and give it a wiggle. If the post moves in the ground, the panel was never the problem. Timber posts that have been in for 15 years or more will rot at ground level. Below the soil they can look solid. Above the soil they can look solid. At the soil line, where the wood's been damp and exposed to air at the same time, they turn into Weetabix. Tap it with a screwdriver. If the tip sinks in, it's gone.

Concrete posts have a different problem. They don't rot, but they crack. A crack near the base usually means the concrete spur underground has broken. Spur's doing the structural work. If the spur's gone, the post's going with it.

The three usual fixes

1. Metal post spike (quickest fix)

If the panel is sound and the post is rotten but the hole is still usable, a metal post fix (like a Metpost spur driven next to the old post) is the quickest fix. Drives into the ground on the sound side. Attaches to the old post above the rot. Buys you another 10 years. About £25 for the spur, an hour of work.

2. Full post replacement

Timber post is knackered and the panel's slid out. Best to put in a new post, either concrete (50 years, won't rot) or pressure-treated timber with a Postsaver sleeve (25 years). Concrete is the long game. Timber is what most people still pick because it looks right.

Cost for a single post swap around £95 to £150 depending on what's underground. If the previous post has a big concrete footing in the wrong place, it takes longer to dig out than to put in.

3. Straighten and brace

If the post's only leaning, not rotten, you can sometimes straighten and brace. Pack the base with postcrete, add a temporary diagonal brace till it sets, job done in an hour. Only works if the timber's still sound.

The boundary question nobody wants to have

Whose fence is it? Check your deeds. Usually marked with a T-symbol pointing into the garden of whoever owns it. If the T points into your garden, the fence is yours to maintain. If it points into the neighbour's, it's theirs, and they're not obliged to fix it. Both of you can agree to split the cost of a new fence, which is where the polite conversation over the hedge comes in.

I've replaced plenty of fences where the two gardens went halves. I've replaced fewer where someone tried to rebuild their neighbour's fence without asking and then wondered why they weren't speaking. Don't be that person.

A note on the Cotswolds

Our soil isn't helpful. Lots of it is heavy clay sitting on limestone. When it gets wet it holds water against timber. When it gets dry it shrinks and pulls posts over. Concrete posts win out here more than people expect.

Rough timings

• Post spike repair, one post: 45 minutes
• Full post replacement, one post: 90 minutes plus setting time
• Short run, three panels and two posts: half a day
• Long run, replacing the whole back boundary: 1 to 2 days

If you're not sure which fix applies, take a couple of photos and text them over. I can usually tell from the pictures whether it's a quick brace or a proper rebuild, and give you a price without having to come out.