When planning your fence, one of the first questions you’ll face is what size concrete posts you need for a 6ft fence. The posts you choose directly affect the strength and lifespan of your fence. For a 6ft fence, you need posts that can handle the weight and wind pressure all year round.
Recommended Concrete Post Sizes
For a 6ft fence, use concrete posts that are at least 8ft (2.4m) long. This allows you to set around 2ft of the post into the ground, giving the fence proper support.
Post width matters too. Standard concrete posts for a 6ft fence are typically:
- 100mm x 100mm (4″ x 4″)
- 125mm x 100mm (5″ x 4″)
If you’re fitting heavy-duty panels or dealing with strong winds, use the larger 125mm option.
How Deep Should Concrete Posts Be Set?
The rule of thumb is to bury one-third of the post’s length. For a 6ft fence, set posts about 2ft deep. This depth keeps the fence stable against wind and ground movement. Use a strong concrete mix and let it fully cure before attaching panels.
Types of Concrete Posts
You’ll come across two common types:
- Slotted Concrete Posts– These let you slide panels directly into the post slots. They are quick to install and make panel replacements easy.
- Morticed Concrete Posts– These need timber arris rails and are often used with closeboard or featheredge fencing.
Most garden fences use slotted posts due to their simplicity.
Installation Tips
- Use a post hole digger to get clean, deep holes.
- Pour concrete evenly around the post and check it’s level.
- Brace the post until the concrete fully sets.
- Use gravel boards to keep fence panels off the ground and prevent rot.
Factors That Influence Post Size
You may need to adjust your post choice depending on:
- Soil conditions– Loose or clay-heavy soil might require deeper posts.
- Wind exposure– Exposed sites benefit from thicker posts.
- Fence type– Heavier panels need stronger posts.
Quick Reference Table
| Fence Height | Post Length | Post Width | Depth in Ground |
| 6ft | 8ft (2.4m) | 100mm or 125mm | 2ft (600mm) |
More Guidance
Getting the post size right makes sure your fence lasts and stays strong, saving you time and money in the long run.
