Quick answer: for a normal 6ft DuraPost fence, we would still work around 600mm post depth and allow roughly 1.5–2 bags of 20kg Postmix per post. The post is lighter and slimmer than timber or concrete, but you still need enough footing mass to stop the fence moving.
Before buying individual parts, see the full DuraPost Fencing range or use our DuraPost VISTA Fence Calculator for a complete composite run.
Set the whole fence run out before digging
Birkdale installation guides often demonstrate the fence progressing one bay at a time. Our preference is to set out the whole run first. Mark the line, check post centres, corners, gate positions and levels, then keep checking them as the job progresses.
Being methodical at the start is much easier than discovering several bays later that the run has drifted.
Dig DuraPost fence posts around 600mm deep
For a typical 6ft fence, we would still start at around 600mm below ground. DuraPost is lighter than concrete, but the footing still has to resist the leverage of the complete fence in the wind. The depth is there to prevent tipping, not simply to hold up the weight of the post.
Allow around 1.5–2 bags of Postmix per post
We would use the same practical allowance as a normal timber post: roughly 1.5–2 × 20kg bags per DuraPost. The slim steel profile displaces less material in the hole, so being lighter does not automatically mean it needs less concrete around it.
Use our 20kg Rapid-Set Postmix and follow the instructions on the bag.
Follow the DuraPost fixing pattern
Use the fixings and positions specified for the system. Missing fixings may not look important while the fence is still, but they can allow panels or profiles to move and rattle once the wind gets behind them.
You can cut DuraPost steel posts
An angle grinder is perfectly suitable. For trade use, a metal-cutting mitre saw or portable bandsaw is also a good option.
After cutting, protect the exposed metal. DuraPost supplies colour-matched touch-up paint for coated posts, while suitable galvanising paint can be used on galvanised steel. Check the manufacturer's current maintenance instructions where bare steel has been exposed.
Expect small scratches during installation — then touch them up
A spirit level falls over, a drill slips, a tool catches an edge. DIYers and professional installers both mark posts occasionally.
Check the coating after each stage and again when the fence is complete. Touch up chips and scratches promptly so water and air are not left sitting against exposed steel.
On slopes, control the top line with the gravel board section
Whether you step the fence or follow the angle of the garden is mainly an appearance choice. We prefer a fence that follows the garden where the layout suits it, but either method can work.
The ground is rarely a perfectly consistent slope. Plan enough depth below the fence to absorb small changes with the gravel-board section rather than letting the top line wander.
Dug-in posts are our preference, but bolt-downs have their place
We prefer a DuraPost set into the ground. If the manufacturer approves a bolt-down support for the chosen fence height and application, however, that means the system has been designed and tested for it.
The concrete base must be sound, flat and level. If the shoe starts out of level, getting the finished post plumb becomes unnecessarily difficult.
Remove old concrete where practical
If an old footing is directly where the new post needs to go, we would normally prefer to remove enough concrete to install the post correctly. Where that genuinely is not practical, a suitable bolt-down may be an option if the remaining concrete provides a sound, flat and level base.
Fixing a DuraPost U-channel to a wall
Concrete screws are a good option for many sound masonry installations. On older brickwork where mechanical fixings will not bite reliably, resin fixing can be a better alternative. Plan for a second fixing method rather than simply fitting a bigger mechanical fixing into weak masonry.
Check existing fence panels before ordering
DuraPost is still a relatively specialised system and not every timber panel is manufactured to the same width. Panels intended for wider concrete-post slots can occasionally need trimming to fit neatly into DuraPost.
If you are reusing existing panels or buying them elsewhere, measure first.
Planning the complete job? Browse DuraPost Fencing, or read DuraPost Problems: Is It Any Good? if you are still deciding whether the system suits your project.
