How to Install a Concrete Fence Post: A Step-by-Step Guide
Concrete fence posts are a long-lasting and low-maintenance option for any fencing project. Unlike timber posts, they won’t rot, warp, or require regular treatment, making them a popular choice for supporting both lap panels and closeboard panels. Whether you’re replacing old posts or installing a new fence from scratch, this guide walks you through every stage of the process.
Slotted Concrete Fence Posts
Rapid Set Fence Post Concrete
Why Choose Concrete Fence Posts?
Concrete posts offer superior strength and durability. They can withstand harsh weather conditions, high winds, and soil movement far better than timber alternatives. When paired with concrete gravel boards, they create a fence system that’s built to last decades with minimal maintenance.
Key benefits include:
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Exceptional longevity (often 25+ years)
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Resistant to rot, damp, and insect damage
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Ideal for slotted panel systems
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Compatible with most panel types, including decorative European panels
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Provide a clean, professional finish
Step 1: Plan and Measure Your Fence Line
Mark out your fence line using a string line between two stakes. Measure the width of your panels and posts to calculate spacing. Each post will sit between panels, so allow for the post slot thickness when measuring your total run.
Pro Tip:
Always check property boundaries and underground utilities before digging.
Step 2: Dig the Post Holes
Each hole should be around 600mm (2ft) deep for standard 6ft fences, or deeper if your fence is exposed to strong winds or uneven ground. The hole width should be roughly three times the post width, giving enough space for Postmix around the sides.
Step 3: Position the First Post
Place the first concrete post into the hole and use your spirit level to ensure it’s perfectly vertical. It helps to prop it temporarily with timber supports or wedges while pouring the mix.
Step 4: Add Postmix or Concrete
Pour Postmix evenly around the base of the post, filling the hole to ground level. Add water as instructed on the bag, allowing the mix to set for around 10–15 minutes. Repeat for each post, using your string line to keep the alignment straight and level across the top.
If you’re using a traditional ballast and cement mix, use a mix ratio of 1 part cement to 6 parts ballast, tamping the mix down firmly around the post before smoothing off the top.
Step 5: Insert Gravel Boards (Optional but Recommended)
Once the posts are secure, slot in your concrete gravel boards between them. Gravel boards protect your fence panels from ground moisture and rot, extending their lifespan significantly.
Step 6: Slot in the Fence Panels
With the posts and gravel boards in place, carefully slide each fence panel down into the slotted sides of the concrete posts. Always lift panels with two people to avoid damage or injury, and ensure they sit securely in the gravel board channel.
Step 7: Check Levels and Finish Off
Use your spirit level across the tops of the posts and panels for a consistent finish. Fill any gaps around the base of the posts with soil or decorative aggregates for a tidy look.
Common Questions
How much Postmix do I need per post?
Typically 1.5 to 2 bags per post, depending on hole size and ground conditions. For a full breakdown by post size and fence type, see our detailed guide: How Much Postcrete Per Fence Post.
Can I use concrete posts with closeboard fencing?
Yes — concrete posts are ideal for closeboard systems when paired with closeboard panels or when using gravel boards, rails, and capping for extra durability.
What if my garden is on a slope?
Install each section step-by-step, adjusting the depth of each post to maintain a level top line across panels. For a full walkthrough, read our guide on installing concrete posts on a slope.
Want a Full Installation Guide?
For a more detailed installation covering both concrete and wooden systems, check out our blog:
👉 How to Install Fence Panels
