A fence is only as good as the posts holding it up. Get them plumb, evenly spaced and properly set, and a closeboard line will stand straight for decades. Rush this bit and you’ll be straightening leaning posts by next winter. The good news: with fast-setting Postcrete there’s no mixing, no barrow and no waiting around.
What you’ll need
- Fence posts — allow one more than the number of panels
- Postcrete — roughly one to one-and-a-half 20kg bags per post
- A post hole digger or narrow spade, and a spirit level
- Gravel for the base, plus offcuts to wedge while it sets
- A line and pegs to keep the run straight
Rule of thumb: bury a quarter of the post. A 2.4m post for a 1.8m fence needs a hole about 600mm deep. Dig it roughly three times the width of the post so there’s room for the concrete.
From the yard
Materials we’d use
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eachPrice range: £189.00 through £312.00Available sizes for Closeboard garden gate — choose a quantity and add to basket. Size Price Quantity Add 1.8m tall × 750mm wide £189.00 each 1.8m tall × 800mm wide £192.00 each 1.8m tall × 850mm wide £195.00 each 1.8m tall × 900mm wide £198.00 each 1.8m tall × 950mm wide £210.00 each 1.8m tall × 1000mm wide £222.00 each 1.8m tall × 1100mm wide £240.00 each 1.8m tall × 1200mm wide £264.00 each 1.8m tall × 1300mm wide £312.00 each -
per bag£7.20Sold per bag -
eachPrice range: £12.50 through £19.95Available sizes for Treated softwood post — choose a quantity and add to basket. Size Price Quantity Add 2.1m £12.50 each 2.4m £14.95 each 2.7m £17.50 each 3.0m £19.95 each
Step by step
1. Set out the line
Run a string line between your end posts and mark each post position — 1.83m centres for standard panels. Measure twice; a wrong spacing here means a panel that won’t fit later.
2. Dig the holes
Dig to about 600mm, keeping the sides clean and roughly square. Drop 100mm of gravel in the bottom for drainage — standing water is what rots a post first.
3. Stand the post & check plumb
Stand the post on the gravel, hold it against your line and check it’s plumb on two adjacent faces with the spirit level. Wedge it with offcuts so it holds while you work.
4. Pour the water, then the Postcrete
Pour water into the hole to about a third full, then add the Postcrete straight from the bag — no mixing. It draws the water up as it goes. Top up so it finishes just proud of the ground, sloped away from the post to shed rain.
5. Re-check and leave to set
Check plumb one last time and adjust within the first minute or two — it starts to firm in around ten. Leave it well alone for an hour before you hang panels, and ideally overnight before any real load.
Tips from the yard
- Brush-treat the cut ends. Any post you’ve trimmed has lost its treatment on the cut face — paint it with end-grain preserver before it goes in the ground.
- Use gravel boards. Keeping the timber panel clear of the soil is the single biggest thing you can do to make a fence last.
- Work in threes. Set three posts, hang the two panels between them, then move on — it keeps everything aligned far better than concreting a whole run first.
Spend the time underground. Nobody admires a fence post — but a leaning fence is the first thing everyone notices.
Shop this project
Everything you need to set a fence line right, milled and stocked at the yard.