How deep should fence posts go, and how far apart?
About a quarter of the post in the ground in the UK, deeper where there's frost. Spacing follows the panel or rail length.
In the UK and Ireland, a common rule is a quarter of the post length in the ground. For a 1.8 m fence that means a 2.4 m post with 600 mm buried. Panel fences set the spacing for you at about 1.83 m centres.
In the US and Canada, posts usually go about a third of their length down and below the local frost line. Spacing is often 6 to 8 ft, set by the rail length.
Exposed, windy spots want deeper holes and more concrete, or slotted concrete posts, which don't rot at the ground line.
Check before you buy or dig
- Call before you dig. Services under gardens are more common than people expect.
- On a slope, step the panels rather than racking them, and count the extra post length on the downhill side.
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Count posts and panels for your fenceA general answer, not a structural design. Local rules, ground and loads decide the final build.