How to Build a Perimeter Fence: From Posts to Boards, Step by Step

Step 1 — Lay out and mark the posts

Mark the two corners of the run with stakes and pull a string line between them — that line guides each post's position. For 20 m with posts every 2.4 m (8 ft) you need 10 posts (9 sections plus one extra at each end). → Fence calculator gives you the exact number for your spacing.

Step 2 — Dig and pour the posts

Dig each hole to the diameter and depth your calculator gives (default 30 cm / 12 in diameter × 60 cm / 24 in deep — one third of the post's visible height). Set the post, check it's plumb with a level, and pour the concrete: for 10 posts at those dimensions that's 0.445 m³ ≈ 20 bags of 50 kg. Let it cure 48-72 hours before loading weight onto the posts.

Step 3 — Install the horizontal rails

With 2 rails per section (top and bottom) across 9 sections, you need 18 rails. Attach them to the now-cured posts, checking they're level with each other — any dip in the rails shows up in every board mounted on top.

Step 4 — Install boards or pickets

With 14 cm (5.5 in) boards plus a 2 cm (0.75 in) gap (a 16 cm module), the 20 m run needs 125 pieces. Start from one corner and use a fixed spacer between boards to keep the rhythm constant across the whole run.

Materials list and work order

10 posts	per the material you chose (wood, metal)
20 bags of concrete (50 kg)	to pour the 10 holes
18 horizontal rails	2 per section, 9 sections
125 boards or pickets	16 cm module (board + gap)

If the fence line crosses an area with poor drainage, consider a layer of gravel along the run to keep water from pooling at the posts. Every quantity in this guide comes straight from the fence calculator — swap in the length and spacing for your own project.