Closeboard Fencing: Specification & Build Detail
Closeboard is built board-by-board on site from feather-edge timber and arris rails — slower and more expensive than a panel fence, but individually repairable and typically longer-lived.
Closeboard fencing is the traditional boundary build for anyone who wants a fence that can be repaired board-by-board rather than replaced panel-by-panel. Because it's constructed on site rather than delivered as a unit, the quality gap between a well-built and poorly-built closeboard run is much wider than with a panel fence — the spec detail below is what separates the two.
This is the fence we recommend most often for long rear boundaries and side returns where privacy and durability matter more than the fastest install.
Checklist before you buy
- Confirm board width and overlap in the written quote
- Ask whether rails are morticed into posts or surface-fixed
- Check gravel board is included so timber doesn't sit on soil
- Confirm post spacing (2.4–2.7m) matches the quote length
- Ask about re-treatment interval to keep your warranty (if any) valid
Board size, overlap and orientation
Feather-edge boards taper from roughly 22mm to a few millimetres across their width, and are hung vertically overlapping by 12–15mm so there's no sightline through the fence even as the timber moves seasonally.
Standard board width is 100–150mm; narrower boards give a tighter, more formal look and use more timber, wider boards install faster but show gaps sooner if the timber shrinks.
Arris rails and post spec
Boards are nailed to horizontal arris rails — triangular-section timber that sheds water better than a square rail. A 1.8m fence takes three rails (top, middle, bottom); anything shorter can run with two, but we don't recommend it on an exposed boundary.
Posts are 100×100mm pressure-treated timber (or concrete, see our concrete post page) set at 2.4–2.7m centres, in concrete to a minimum 600mm depth. Rail ends are morticed into the post, not just face-fixed, on a proper build.
- 3-rail build as standard on 1.8m closeboard runs
- Morticed rail joints, not surface-screwed brackets
- Gravel board beneath the boards so no timber touches soil
- Post caps fitted to shed water off the end grain
Lifespan, maintenance and when it's the wrong choice
A properly specced closeboard run in pressure-treated softwood with concrete posts typically lasts 15–20 years, longer on the boards with a re-treat every 3–4 years to keep them tight against shrinkage gaps.
It's the wrong choice where speed and lowest cost matter most — a comparable panel fence installs in a fraction of the time — and it's harder to build well on a steep slope without stepping the runs, which adds labour.
Frequently asked
How is closeboard different from a panel fence?
Closeboard is built on site board-by-board on rails between posts; a panel fence is pre-made panels dropped between posts. Closeboard costs more in labour but individual boards can be swapped without touching the rest of the run.
How often does closeboard need re-treating?
Every 3–4 years on an exposed boundary to keep the boards tight and prevent premature greying, sooner in deep shade where timber stays damp longer.
Can closeboard be built on a sloping garden?
Yes, either stepped (each bay level, small drops between bays) or raked (rails follow the slope) — stepped gives a tighter fit but costs more in labour.
What post spacing do you use for closeboard?
2.4–2.7m centres is standard for a 1.8m fence; we tighten this on exposed sites or where the run will carry a gate.
Can I add a trellis top to closeboard fencing?
Yes — trellis toppers fix to the top rail and typically add 300–450mm of height for planting screening without triggering the same height rules as solid boarding.