Rotting fence posts prove to be a growing problem

Rotting fence posts that have only been in the ground a few years – does that sound like a familiar scene? Well judging by readers on Farmers Weekly forums it is a growing problem.

And the reason why is due to a change in legislation, according to director of Postsaver, Richard George. He says due to a change in EU legislation in 2005, which banned the use of certain timber preservatives, the new products used are not as easy to use, making preservation harder.

“The new preservatives require wood to be prepared carefully before treatment. This has made it difficult for the industry and as a result, we are seeing some fence posts lasting only three to five years instead of 15 years,” he says.

Fence posts will always rot below ground level with ground conditions determining the rate of decay. “The highest rate of decay is within two to three inches of ground level and mechanically is the most highly stressed part of the post,” he says.

Alternative products are available to protect fence posts but preservation can be quite difficult and some people are beginning to loose confidence.

Mr George says using a sleeve that heat shrinks on to the ground line section of a fence post can help seal the surface and is a barrier against micro-organisms.

“I have phone calls from farmers all the time looking for solutions. Using an extra barrier has the potential to save a lot of money in the long run, but for not much more money at the outset. To install 200m of stock fence it would normally cost about £600 without a sleeve or £660 with, so the initial investment is worth it,” he says.

From the Forums

• Owd Fred on the forum has had some success buying posts pressure treated and also suggests buying posts made from recycled black plastic. “No amount of painting the posts on the outside is going to make much difference to how it will last,” he says.

• Allry R adds: “Our farm is pretty well drained so we moved on to treated timber posts. Our local sawmill uses a pressure treatment tank for this job which is supposed to make the preservative penetrate much deeper in to the wood. We used to think that these preservative treated posts were more brittle and liable to break than the untreated ones.”

• Avalon says: “Treated larch posts should last 20 plus years. We have a fence erected just after the war with pressure treated tar post which are still ok.

• Hillsalive says he had to replace all of his 3×3 fence in 18 months as they had gone rotten on the ground line. “I now use a sleeve that goes on the ground line section of the post and stops the rots. It took me about 40 seconds to apply with my blow gun and I feel happier about installing a fence with this protection and at 59p a sleeve it’s well worth it.”

• For more tips on preserving fence posts or to join the discussion on our online forum.

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