Winter rarely arrives politely. A fence that shrugged off a dry summer can be leaning by February, and it is almost always water rather than cold that does the damage: rain pooling around a post, frost expanding saturated ground, a gale finding the one panel held by two loose nails. Catch the problems in autumn, on a dry afternoon, and most of them cost you a screwdriver and a tin of preserver rather than a new run of fencing.
Walk the whole run before you touch anything
Do this job in daylight, ideally a day or two after rain when the ground is soft enough to show you where water sits. Take a notebook, a thin screwdriver, gloves and a torch. Work along the fence methodically, then come back and look at the other side. Your neighbour's side is often where the rot is hiding, because that is the face you never see.
Note anything that fits the following:
- Posts leaning, or sitting lower than their neighbours, with soil cracked around the base.
- Rails that have dropped, twisted or popped away from a post.
- Boards that have cupped, split or gone soft and dark along the bottom edge.
- Nails or screws that have rusted through or pulled proud of the timber.
- Soil, compost, gravel or bark chippings banked up against the fence.
- Anything pressing on it: a shrub, a shed roof, a bin store, a climbing rose you have been meaning to cut back.
Photograph the problem spots. It makes ordering the right parts much easier than guessing from memory.
Posts: what is happening below ground matters most
Testing for rot
Push a thin screwdriver into the post just above ground level, then again a hand's width lower if you can reach. If it sinks in easily, or the wood comes away crumbly and orange-brown, the post has gone, however solid it looks a metre up. Look too for dark staining, a spongy feel under thumb pressure, or a line of white fungal growth where the timber meets the ground. That last one usually means water has been sitting there for a while.
What to do about it
Surface rot in the top third of a post is often treatable: scrape back to sound wood, let it dry and soak in a wood preserver. Rot at the base is not a repair job. Either dig the post out, extend the hole and re-set it in concrete, or, if the post is otherwise sound, bolt a metal repair spur alongside it and drive that into the ground. A spur is a decent fix rather than a permanent one, but it will get you through a winter.
If you are replacing posts, choose timber rated for ground contact, or go for concrete, steel or a composite. Set the concrete slightly domed at the top so rain runs off rather than pooling around the post, and keep the base of the fence clear of soil so air can move around it.
Panels, rails and fixings
Tap along the bottom edge of each panel with the handle of a screwdriver. A dry, hollow ring is fine; a dull thud with a bit of give to it is not. If the panel frame is sound, you can usually replace two or three boards rather than the whole panel, which is cheaper and much less disruptive.
Pay attention to the fixings. Timber shrinks and swells through the seasons, and nails work loose as it moves. A panel that rattles in a breeze is already damaging itself, because every gust levers the rails a little further off the posts. Replace loose nails with galvanised or stainless steel screws, and check the rails as well as the boards.
Gates and their hardware
A gate takes more punishment than any other part of a fence, and it usually fails in a way you can predict.
- Check the hinges. If the gate has dropped, it is normally because hinge bolts have worked loose or the hanging post has shifted. Tighten or replace the bolts and see whether the gate lifts back into line.
- Test the latch. A latch that has stopped meeting is usually a symptom of a dropped gate, not a faulty catch. Fix the cause before you adjust the latch.
- Look at the brace. On a braced gate, the diagonal should run from the bottom of the hinge side up to the top of the latch side. If it runs the wrong way, the gate will sag and there is not much you can do about it short of rebuilding.
- Clear the ground. Aim for a hand's width of clearance under the gate so it does not drag, and so the bottom rail is not sitting in wet grass all winter.
- Oil the moving parts. A drop of light oil on the hinges and latch keeps them working through the wet months.
If the gate post itself is soft at the base, treat that as urgent. A hung gate places a lot of load on a post, and a gale can turn a wobbly gate into a flying one.
Drainage and the ground around the fence
Frost heaves whatever is wet. Saturated ground expands as it freezes, pushing posts out of line and cracking concrete around them. Sort the water and most other problems become manageable.
- Clear leaves, moss and debris from along the base of the fence, especially in corners where it collects.
- Check gutters and downpipes. A downpipe discharging onto the soil beside a fence will rot the posts within a few seasons; redirect it into a drain, a water butt or a gravel soakaway.
- Find the low spots. If the ground slopes towards the fence, a shallow gravel-filled channel alongside the run will move water away rather than letting it pool.
- Keep soil and mulch below the bottom rail. Banking material against timber holds moisture right where it does the most damage.
If the fence sits on top of a retaining wall or there is a significant change in ground level nearby, get a professional to look at it. That is a structural question, not a fencing one, and it is worth the money.
Cleaning and treating timber
Scrub off algae and green mould with a stiff brush, using a diluted patio or deck cleaner and a rinse afterwards, then leave the timber to dry properly. Most water-based preservers and stains need dry conditions and a few degrees above freezing to cure, so watch the forecast and pick your window. Pay particular attention to cut ends and the base of posts, which soak up water faster than anywhere else. Never paint or treat damp timber: you will trap the moisture inside and speed up the rot.
Metal hardware benefits from the same attention. Touch up any chipped paint on brackets and gate fittings before rust takes hold, and replace screws and bolts that are already corroded. On composite or plastic fences, check that panels are still clipped in and wash them down with warm soapy water.
Before a storm is forecast
There is a useful hour's work to do whenever a named storm is heading your way. Tie back or cut back climbers that pull on the fence, move anything leaning against it, and secure bins, pots and trampolines that could be blown into it. If a panel is already loose or a post is soft, take the panel down and store it flat rather than leaving it to become a projectile. Never work at height in strong winds, and if anything ends up touching an overhead power line, keep well clear and call your electricity network operator rather than trying to move it yourself. Before digging out a post, check for buried cables and pipes; your utility providers or a free line-search service can tell you what is down there.
Do the urgent bits first
You do not need to do everything on this list. Prioritise in this order: any post that is soft at the base, anything that would fly in a gale, and any water currently running onto the fence. Everything else, the grey boards and the squeaky latch, can wait for a milder day in spring. One dry morning in autumn, a screwdriver and a little patience will save you a weekend of rebuilding in March.
Photo: Pavel Danilyuk / Pexels