Concrete spur fence post repair.
Related articles
Installing a wooden garden fence
How to install a concrete fence spur.
One of the first parts of a timber fence to fail is the base of each post. Years of damp soil laying against the post will eventually rot the timber, causing the fence to become unstable or collapse. When the posts are allowed to move, the fence panels can pull apart so it’s vital to repair the post as soon as possible
A concrete fence spur acts as an extension to the existing timber post and allows you to re-concrete the post into the ground. Being steel reinforced concrete, the spur will not rot and offers a permanent solution.
There are three options when it comes to dealing with a rotten fence post:
- Replace the post.
- Install a concrete fence spur.
- Pay somebody approx. £60-80 to install the spur for you.
If you're feeling fit, here's a quick guide to repairing a fence post using a concrete spur.
Breaking through the old fence post concrete.
The first step is to dig out one side of the existing concrete post support. This can be quite a difficult job depending on the cement content of the concrete originally used.
You want to split the concrete so you can drop the spur into the hole and affix it to the post. Use a steel demolition bar to split and remove the concrete as shown in the photos. Alternatively, if you have access to a powered breaker or Kango, you'll find this part of the job easier.
If you're lucky, the post will have been installed using a Metpost support and you won't have to break any concrete at all, in which case it would be better to install a new fence post using the methods described in our fencing article.
Once the concrete has been removed from one side of the rotten post base, you can drop the spur into the hole. Make sure there is no remaining concrete preventing the spur from resting flush against the fence post. You need at least 2 feet of spur below ground level, so you may need to make the hole deeper. Post hole diggers will make the job easier.
Fixing the concrete spur to the post.
The spur is fixed to the fence post using two (or sometimes three) coach screws and washers. The length of coach screws needed depends on the thickness of the concrete spur. If the spur is 3 inches thick, get 5 inch coach screws so you have 2 inches of coach screw to go into the fence post. If the post is softwood (most are) you won’t need to pre drill the holes - just give them a tap with a hammer to start them off. If the post is oak, you will need to pre drill the holes to prevent the coach screw from shearing.
Concreting the fence spur.
Once the spur is firmly fixed to the post, it’s time to concrete the spur in place. You can either use a semi dry mixture of cement and ballast (mixed 5:1 or 4:1) rammed into the hole, or a pre mixed material such as Postcrete. Postcrete works quickly but will cost a bit more than mixing your own concrete. For directions on the ramming method of concreting, see our guide to fencing with panels. Make sure the post is level before you begin adding the concrete.