Useful UK video guide to the full job. This walk-through is based on "How to Replace a Damaged or Rotten Fence Post", from the Buy Sheds Direct channel. It covers removing the old post and concrete base, setting a new post at the right depth, and getting the fence panels back on straight.
1. Check what you are dealing with
Push the post firmly at the top. If it rocks easily or breaks away in your hand at ground level, it needs replacing. A post that is simply leaning but still solid in the concrete may be salvageable with a repair spike or spur instead.
Also check whether the post is set in concrete. Most UK garden fence posts are. That concrete needs to come out with the post, which takes a bit more effort but produces a cleaner result.
2. Remove the fence panels first
Take the panels off before you start on the post. They are heavy and awkward, and having them propped against the fence while you dig makes the whole job harder.
Most panels are held in place by clips or battens nailed to the post. Remove any nails carefully and store the panels flat or lean them somewhere stable. East Kent gardens are not always big, so a bit of planning here saves a scraped shin or a damaged panel.
3. Dig out the old post and concrete
Use a spade to clear the soil around the base of the post, exposing the concrete collar. Then use a crowbar or post-puller to lever the whole thing out. If the concrete is stubborn, dig around it more before trying again rather than just yanking harder.
Alternatively, if the post has rotted right through, you can sometimes snap it off and then break up the concrete in the hole and remove it in chunks. Either way, you want a clean hole to work with.
4. Prepare the hole
The hole should be about 600mm deep for a standard 1.8m garden fence. That said, taller fences or exposed sites need more depth. A third of the post length in the ground is a reasonable rule.
Clear out any broken concrete, loose soil and debris. If the base is very wet or soft, add a few inches of gravel for drainage before setting the new post.
5. Choose and prepare the new post
Use pressure-treated timber - it makes a real difference to how long the post lasts in the ground. Green-treated posts are the most common and readily available from any timber merchant or builders' merchant.
If your old post was 100mm x 100mm (a common size), buy the same. Cut it to length if needed, and chamfer or cap the top so water runs off rather than soaking in.
6. Set the new post
Drop the post into the hole and check it is plumb in both directions using a spirit level. Prop it temporarily while you do this - two angled offcuts of timber work well as braces.
Fill around the post with post-mix concrete (a dry-mix bag that you add water to directly in the hole) or mixed concrete. Work it in around the sides, tap to remove air pockets, and taper the top away from the post slightly so water drains off.
Leave it to set properly - at least four hours for post-mix, overnight is safer. Do not hang any weight on it before it is fully cured.
7. Reattach the fence panels
Once the concrete has set, refit the panels. Make sure each panel is level before fixing. Use galvanised nails or screws rather than plain steel, which will rust and stain the wood within a season or two.
If the panels themselves are damaged or warped, this is the time to replace them. It is a lot easier to do while the fence is already in pieces.
When to call a handyman
Call Richard if there are several posts to replace, the ground is very hard or stony, the fence runs along a boundary shared with a neighbour, or the existing panels need replacing as well. Fencing work piles up quickly once you start pulling things apart.
Need a fence post replaced in Sandwich?
The Sandwich Handyman can replace rotten or damaged fence posts, sort loose panels, and carry out other garden fencing repairs around East Kent.
Contact Richard