A fence rarely gives up all at once. More often one part fails, a post works loose or a panel blows out in a gale, and suddenly the whole run looks tired even though most of it is sound. The decision people reach for is usually too big: rip it all out and start again. The more useful question is narrower. What has actually failed, and is that the part holding everything else up?
Start at the posts
The posts decide most of these calls, because they carry the load and everything else hangs off them. A cracked panel on a solid post is a quick fix. A perfect panel on a rotten post is still a failed fence, and no amount of replacing boards will save it.
Check each post properly rather than eyeballing the run. Give it a firm push at the top and see how much it moves; a post that rocks in the ground or flexes at the base is going. With timber posts, the failure point is usually right at ground level, where wet soil and air meet, so a post can look fine at eye height and be crumbling where it matters. Concrete posts last longer at that wet base level but can crack, and a concrete spur bolted to a leaning timber post is a common halfway repair worth considering before a full dig-out. If the posts are sound and it’s only the panels that have suffered, you’re firmly in repair territory.
Panels, boards and the parts between them
When the posts pass the test, most of what’s left is straightforward to swap. A panel that’s cracked or pushed out by wind can usually come out and a new one drop in between existing posts, assuming the posts are a standard spacing. Gravel boards take the worst of the ground moisture along the bottom edge, and they’re cheaper to replace than the panel they protect, so renewing those while leaving good panels in place is often the sensible middle option. Rails and capping fall into the same bracket of jobs that don’t need the whole fence touched.
One honest caveat: matching new timber to a weathered run rarely looks seamless at first. New panels sit brighter until they’ve had a season to grey down, which is worth knowing before you expect an invisible repair.
Work out why it failed
Before repairing anything, it’s worth understanding what did the damage, or the same thing happens again. Posts set straight into soil rather than concrete tend to loosen sooner. A spot where water pools at the base rots timber faster. And an exposed, windy boundary puts far more load on solid panels than a sheltered one, which is why panels blow out in some gardens and never in others. A more open style of panel lets wind through and can survive an exposed site better than a solid one.
Check the boundary before anyone picks up a spade
This part gets skipped and causes real trouble. Confirm which fence is actually yours before altering it, since the responsibility for each boundary is usually set out in the property deeds and isn’t always the side people assume. Don’t fix anything to, or remove, a neighbour’s fence without agreeing it with them first. Height can matter too, as there are limits above which permission may be needed, so a taller replacement isn’t automatically a free choice.
What a full replacement actually needs
If the posts have gone along most of the run, a full replacement often makes more sense than chasing repairs down the line. At that point it helps to work out the complete set of parts before starting, because running short halfway through a dug-up boundary is miserable. A run needs posts, gravel boards, panels or featheredge boards and rails, post fixings or postcrete, and capping to finish, and it’s easier to price up and order those fencing materials together once the run is measured than to piece them together over several trips. Work out quantities from the actual length of the boundary, and before digging any post holes, check for underground services so a spade doesn’t find a cable or pipe.
Doing it yourself or bringing someone in
A competent DIYer can manage a panel swap or a single post with a hand to help, though posts, concrete and full panels are heavy and awkward, and digging out an old concreted post is harder work than most people expect. A long run, sloping ground, or a boundary where the levels step down is the point to consider a fencing contractor, both for the labour and for getting the line and the post spacing right.
Look at what’s actually failed before deciding anything. A fence that’s only lost a couple of panels doesn’t owe you a full rebuild, and the posts will usually tell you which job you’re really facing.