How to Install a Wooden Fence Post – Step-by-Step Guide
Learn how to install a wooden fence post properly using Postcrete or concrete. This step-by-step guide covers depth, alignment, slope adjustments, and curing tips for long-lasting garden fencing.
Wooden Fence Post
Rapid Set Post Concrete
Why Fence Post Installation Matters
Your fence posts are the foundation of your entire fence. If they’re not set correctly, your fence will eventually lean, loosen, or collapse — no matter how strong the panels are.
By taking time to dig to the right depth, use enough Postcrete, and ensure solid alignment, you’ll create a structure that stays upright for decades.
This guide explains how to install a wooden fence post step by step, whether you’re building a closeboard fence, lap panel fence, or a small picket fence.
Tools & Materials You’ll Need
Materials
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Postcrete or a ballast/cement mix
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Gravel boards (optional)
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Post saver sleeves (recommended)
Tools
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Post hole digger or spade
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Spirit level
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Tape measure
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Bucket or watering can
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String line and pegs
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Rubber mallet
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Timber supports for bracing
Step 1: Mark Out Your Fence Line
Start by marking where each post will go.
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Use a string line and pegs to create a straight boundary.
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Mark post centres according to your fence panel width (usually 1.83 m or 6 ft).
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Double-check the spacing for gates or corners.
This ensures your fence panels fit perfectly without cutting or adjusting them later.
Step 2: Dig the Post Holes
Each post hole should be:
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600mm (2ft) deep for a 1.8 m (6 ft) fence
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50-100mm wider all around than the post itself
This allows for even coverage of Postcrete or concrete around the post.
Tip:
If your post is 150 mm x 150 mm, dig the hole 50–100 mm wider all around.
This helps you achieve good concrete coverage and prevents direct soil contact.
On sloped ground, dig slightly deeper on the higher side to compensate for the drop and maintain a level top line.
👉 For more details on depths and soil types, see our companion guide:
How Deep Should a Fence Post Be?
Step 3: Set the Base and Drainage
Before placing the post, add a small layer (around 100 mm) of gravel to the bottom of the hole.
This helps with drainage and prevents water from pooling around the timber.
Step 4: Position the Post
Place your post in the centre of the hole.
Use a spirit level to ensure it’s perfectly upright on both faces.
Temporarily brace it with a few offcuts of timber to keep it steady.
If you’re using post saver sleeves, slide one on now to protect the timber at ground level from rot.
Step 5: Add Postcrete or Concrete
Pour Postcrete evenly around the post — don’t dump it all in one side.
Add water directly into the hole as you pour, roughly 2–2.5 litres per 20 kg bag.
Use 1.5–2 bags per post depending on hole size and post thickness.
Mix with a stick or trowel for even wetting.
Hold the post steady for around 5 minutes while the Postcrete starts to firm up.
For larger or structural jobs, you can use a 5:1 ballast-to-cement mix instead, but Postcrete is cleaner and much faster for typical garden fences.
Step 6: Check Level and Alignment
As the Postcrete sets (within 10 minutes), check:
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The post remains vertical both front-to-back and side-to-side.
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It aligns perfectly with your string line.
Once level, slope the top of the Postcrete away from the post to direct water runoff.
This prevents moisture pooling and helps the post last longer.
Step 7: Allow to Cure
Although Postcrete sets within 10–15 minutes, avoid attaching panels or rails for at least 24 hours to allow full curing.
Once cured, remove the braces and trim the top of the post if necessary.
Step 8: Fix Fence Panels or Rails
After curing, you can attach panels or feather edge rails depending on your fencing system.
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For lap panels, use brackets or clips.
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For closeboard fencing, nail rails between posts first, then fix boards and capping.
If your fence includes gravel boards, install them now before attaching panels — they’ll protect your posts and panels from ground contact.
Step 9: Finishing Touches
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Apply timber preservative or UV-resistant oil to the exposed sections.
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Check fixings annually.
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Recoat with preservative every 1–2 years to maximise lifespan.
Common Mistakes to Avoid
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Shallow post holes: posts should be buried one-third of their length.
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Uneven concrete: causes leaning over time.
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Skipping drainage: water pooling leads to rot.
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Attaching panels too early: can twist or stress uncured posts.
Clarke Fencing Ltd – Supplying quality fencing, timber, and landscaping materials across Suffolk and East Anglia since 1984.
