Replacing a Collapsing Boundary Fence

Not every job is a kitchen. This one was two days of fencing, and it is worth writing up because the reason the old fence failed is the reason most fences in the west of Scotland fail, and it is almost never the bit people blame.

It was never the panels

The fence that came out had been painted at some point, which had kept the boards looking serviceable for longer than they deserved. Underneath, the posts had rotted at ground level. A post that has gone at the ground line is doing no work at all, and what was actually holding the run upright was the ivy that had grown right through it. Pull the ivy off and the whole thing comes down.

This is the trap with fence repairs. Replacing the panels of a fence whose posts have gone gets you a tidy-looking fence that falls over in the first real wind. If the posts move when you push the fence, you are replacing the fence, not repairing it.

Agreeing the line first

Before anything came out we agreed the boundary line with the owner on the other side. This takes ten minutes and it saves an enormous amount of grief. A fence that goes back up 100mm out from where the old one stood is a dispute waiting to happen, particularly on newer estates where the plot boundaries are precisely defined and everyone has the drawings.

How the new run is built

Posts first, set in concrete, deep enough to be below where the ground freezes and generous enough that the concrete collar is doing the work rather than the soil around it. Gravel boards sit between the posts at the bottom so that no vertical board is standing in wet ground. That single detail is most of the difference between a fence that lasts five years and one that lasts fifteen: it is always the end grain sitting in a wet base that goes first.

The boards themselves are pressure-treated and fixed vertically, close-boarded, which gives a run with no visible rails from the garden side and no gaps for a fence panel to catch wind through. Panels act like sails. A close-boarded fence on properly set posts has a great deal more to give before anything moves.

Leaving it tidy

The gravel bed that ran along the old fence was lifted, the ground made good behind the new line, and the gravel reinstated and edged. Everything that came out, including several barrow loads of ivy, went away with us the same day.

Two working days, one of them almost entirely posts and concrete. The concrete wants a day before the boards go on, which is why anyone promising a full fence replacement in an afternoon is fixing boards to posts that have not gone off yet.

When to do it

Late spring through early autumn, if the choice is yours. It is not that timber fencing cannot be installed in winter here, it is that digging post holes in saturated ground makes a mess of a garden you then have to live with. If a fence has already come down and the garden is not secure, that calculation changes and we will come out regardless.