How do you fix a fence post snapped at ground level?

The break point tells you the whole story. Timber posts fail in a narrow band either side of the soil surface, where the wood stays damp and still gets air. The section a foot higher can look and sound perfect while the buried end has gone soft. Trade sources put timber posts at seven to ten years before they need replacing, so if one post on a run has snapped, the posts either side went into the ground on the same day with the same treatment. Test all of them before you commit to a single-post repair.

The method is straightforward and the concrete is what makes it work. Panels come off both sides. The old footing is broken out and carted away, which trade guides budget at £50 to £100 per post before any new material is bought. The new post wants to be at least 100mm by 100mm and treated to Use Class 4 for ground contact. Depth of 600mm is common UK practice, though some installers work to a third of the post length, which is nearer 900mm on a 6ft fence. One bag of Postcrete per post sets in five to ten minutes and panels can be rehung about ten minutes later.

Concrete repair spurs have their place, and it is narrower than the internet suggests. A spur bolted to a stump only works if the buried stump is still sound timber, because the bolts have to pull against something. On a post that has rotted through, the spur has nothing to grip and the repair fails within a season. Driving a metal repair spike alongside an existing concrete footing rarely works either, because the spike hits the old concrete. Where a stump is sound and the fence is otherwise young, a spur can buy several years for less labour than a full post replacement.

Ask what happens to the cut end. Pressure treatment reaches into the timber from the outside, so a post cut to length on site has raw, untreated wood at the cut face. Jacksons Fencing is explicit that timber cross cut or drilled on site must be treated immediately, and its guarantee excludes in-ground timber that was cut, drilled, notched or planed after factory treatment. A cut end buried in wet ground with no end-grain preservative is a rot path into the heart of the post. If you would rather remove the problem, concrete posts do not rot, and the fitted difference is around £10 a post.

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