Planning a Bamboo Fence: Panels, Posts, and the Post You Forgot
A bamboo fence is a short materials list and one arithmetic trap. The trap is the off-by-one in the post count, and it is the kind of mistake you discover at the far end of the run with everything else already in the ground.
Posts are panels plus one
A panel spans between two posts. Two panels share the post between them. So a run of n panels needs n + 1 posts — one at each join, plus one at each end.
From the fence calculator, with 8 ft panels:
| Run | Total length | Gate | Net run | Panels | Posts |
|---|---|---|---|---|---|
| Small garden | 40 ft | none | 40 ft | 5 | 6 |
| Side boundary with a gate | 60 ft | 3 ft | 57 ft | 8 | 9 |
| Full perimeter | 120 ft | 6 ft | 114 ft | 15 | 16 |
The 60 ft boundary with a 3 ft gate needs 8 panels and 9 posts. Counting posts as panels gives 8, and the fence stops one post short of its own end.
Subtract the gate before anything else
A gate is a hole in the fence, so it comes out of the run before the panels are counted. The same 60 ft with no gate needs 8 panels; with the 3 ft gate it needs 8. The gate hangs on posts you are already buying, so it does not add posts — but the gate itself, its hardware and usually a heavier post at the hinge side are all extra.
Panels or poles
Pre-made rolls and panels span between posts and are counted by width. A pole fence lashes individual vertical culms side by side and is counted per unit length instead — which makes it a different order entirely, and far more sensitive to culm diameter, since thinner poles mean more of them for the same run.
Panels go up faster and look uniform. Poles look better as they weather and let you work around an irregular boundary, because you are not committed to a fixed module. Neither is more correct; they are different jobs.
What the numbers assume
One unit throughout. Length, panel width, post spacing and gate width must all be feet, or all metres. The arithmetic does not care which, and it cares very much that they match.
A straight run. Corners need their own posts and interrupt the panel module, so a perimeter is best counted as several runs rather than one long one — which is what the 120 ft row above really is.
Level ground. On a slope you either step the panels, which wastes some of each, or rake them, which not all panels allow.
The post is the part that fails
Bamboo panels weather well. What ends most bamboo fences is the post rotting at ground level, which is why the material and treatment of the post matters more than the panel you hang on it. Set posts in gravel with a free-draining base rather than sealing them into a concrete cup that holds water against the timber, and keep the panel's bottom edge clear of the soil.
Buy a spare post. The calculator's 9 is exactly right, which is precisely why one split during setting leaves you stopped.
Setting the post spacing yourself
If you set posts at a fixed spacing rather than letting the panel width dictate them, the count changes: posts become ceil(net run ÷ spacing) + 1, and the panels have to be cut to suit. That is the right approach on an irregular boundary, where forcing a fixed panel module produces one absurd offcut at the end.
Closer spacing costs more posts and buys a stiffer fence. On an exposed boundary that is usually money well spent, because wind load on a solid bamboo panel is considerable and it is always the post that gives.
Gates need more than a gap
Subtracting the gate width from the run gets the panel count right and nothing else. A gate also wants a heavier post on the hinge side — carrying the swinging weight and the leverage of it — plus a latch post that does not move. Those are frequently set deeper, or in concrete where the fence posts are not.
Leave clearance as well. A gate cut to the exact opening will bind the first damp week.
What makes a bamboo fence last
Keep it out of the soil. Ground contact is where rot starts. A gravel base under the post, a gap under the panel, and the fence ages instead of failing.
Let water leave. A post sealed into a concrete cup holds water against the timber permanently. Set posts in compacted gravel, or slope the concrete away from the post.
Treat the cut ends. A cut culm is an open straw. Sealing the ends keeps water out of the internodes, where it collects, freezes and splits the culm.
Re-tension the lashings. On a pole fence the bindings loosen as the culms dry and shrink in the first season. One pass around the fence a year in is the whole of the maintenance.
Ordering
Take the panel and post counts from the calculator, then add one post and one panel. The counts are exactly right, which is precisely the problem: a post split while setting, or a panel damaged in transit, stops the job on the day rather than costing a little more on the order.
Checking the run before you buy
Walk the line with a tape and write down the segments: straight runs, corners, the gate, and any change in level. A perimeter is several fences, and each one needs its own panel and post count with its own end posts — which is why totalling the whole boundary as a single run understates the posts every time.
Then check what the boundary actually is. A fence set a few inches inside your own line is a fence you can maintain from both sides; one set on the line is a conversation with a neighbour every time it needs work.