Most of the time repairing or replacing fence posts is a hugely awkward, difficult job. Usually the existing wooden post has rotted at ground level because it has been concreted in by someone who did not take 5 minutes to trowel the top of the concrete to a slight dome allowing the rain water to run off. Instead of that, the water sits on the concrete, at the base of the post, slowly rotting and weakening the post until the wind blows the fence panels and the post breaks.
Problem number 1 is the fact that the broken post has to be removed from between the two panels it is fixed to and problem number 2 is the fact that the bottom third of the post (See our project on concreting fence posts) is fixed firmly in a whole wheelbarrow load of concrete.
If you ignore both of these problems then simple remedies like fixing a fence post spur, shown on the left, are available to you.
Concrete spur to a fence post
Fixing a concrete spur post involves digging down alongside the old post and concreting in the new spur. It is always advisable to have, at the very least, 450mm of spur under the ground but 99% of the time the existing fence post concrete stops this happening. If you do not fix a spur solidly it actually helps the fence to wobble about even more!
One answer is to break out the concrete or pull out the whole lump. The concrete can be broken fairly easily with the right tools and these can be seen in our breaking concrete project. Once the concrete, or some of it, is broken out a spur can be fitted properly but by the time you have got to this point you might be feeling its worth carrying on to remove all of the concrete and the old post, and start again with a new post and new concert. We would agree with you !
One small problem here is that, once you have finally excavated all of the post and concrete, you have loosened all of the soil and have a gaping hole looking a little like a bomb crater!
This is easily rectified with some old timber and perhaps a couple of spare paving slabs which can be put inside the hole and used as "formwork" to form a box inside the hole and to hold the new concrete in place.
The image below shows an old hole with bits and pieces of timber pushed in to form new sides around the post in the centre. Some earth is pushed in behind these pieces of timber so when the concrete is tipped in the earth will stop the new sides (Also known as shuttering or formwork) from pushing out.
As long as you have 6 inches of concrete either side of the post it will be strong. Refer to our concreting posts project to see how to keep the water from the top of the concrete.
New concrete into an old hole
The final way of effecting a proper repair to a fence is to ignore the broken post hole completely. This is more of a major job but there are situations where it is far more practical than other methods. It also involves cutting a fence panel down which is a really handy thing to know how to do anyway. See our project on cutting down fence panels.
Inserting half panels into fence
The image above shows the broken post (A). This post is removed and cut off at the very top of the concrete so it finishes below ground level. This leaves the two fence panels flapping in the breeze so they need to be taken off too. Presuming the fence panels are 6 foot panels, dig two new fence post holes in positions D and E and using our project on concreting fence posts, put 2 new posts in.
New panelled fence
One of the panels you have removed is now fitted between posts D and E and the other panel is cut in half and the two halves are fitted between C and D and E and B.
Yes, it is noticeable but if the next door neighbours has a patio which comes right up to the fence………..How many choices have you got ?!