A timber fence is only as good as its posts. We see a lot of fences that have failed within five to eight years, and in almost every case the failure is at the post, not the panel. The panel rots or blows out because the post has moved, rotted at ground level, or was never set deep enough to resist the wind load. None of this is complicated to get right, but it requires doing a few things that take a bit more time and cost a bit more money.

Post depth: the rule most people ignore

A fence post should be set to a depth of at least one third of its total length. For a 1.8m close-board fence, that means a 2.4m post set 600mm into the ground. Most DIY installations use a 2.1m post set 300mm deep, which is not enough to resist a sustained wind load. The post rocks, the concrete cracks, water gets in, and the post rots from the base up. Use the right length post from the start.

Concrete spurs versus setting in concrete

We use concrete spurs at every post rather than setting the timber directly in concrete. A concrete spur is a precast concrete post that is set in the ground, and the timber post is bolted to it above ground level. This keeps the timber out of the soil entirely, which is where rot starts. It adds about £15 to £20 per post but it can double the life of the fence. We have taken out fences set directly in concrete that were rotten at the base within six years.

Timber specification

We use pressure-treated softwood as standard. The treatment should be to UC4 specification for ground contact, which means the preservative has been driven into the timber under pressure rather than just applied to the surface. Timber described as 'treated' without a specification may only have been dip-treated, which gives much less protection. Ask your supplier for the treatment specification before you buy.

Capping and weathering

The top of a fence post is the most vulnerable point after the base. Water sits on a flat-cut top and works its way into the end grain, which is the most absorbent part of the timber. A simple angled cap or a proprietary post cap keeps the water moving off. It is a small detail but it adds years to the post life. We cap every post we install.

Hedging alongside fencing

Where a client has the patience for it, we always suggest planting a hedge alongside a new fence. The hedge provides additional wind shelter, which reduces the load on the fence, and it will eventually replace the fence as the primary boundary. Native species like hawthorn, blackthorn, and field maple establish quickly and provide good wildlife habitat. A mixed native hedge planted at 3 plants per metre will be stock-proof within five years.

If you have a fence that is starting to lean or posts that are rocking, it is worth getting it looked at before the autumn winds arrive. A post that is moving can usually be stabilised with a concrete spur without replacing the whole fence. Get in touch and we will come and have a look.