Palisade Fence Calculator

For BS 1722-12 steel palisade, D-section pales are typically about 65–67mm wide and fixed at 152mm centres (centre to centre), leaving a gap of around 85mm. That gives 17 pales per standard 2.75m bay (18 for higher-security specifications) — the rails are factory-holed 17 times to suit. The 152mm centre spacing is the standard manufacturer figure; always confirm against the specific system's product data sheet, as some security specs use tighter spacing.

Standard palisade heights are 1.8m (general boundary), 2.4m (standard security), and 3.0m (high security). For LPS 1175 rated security, 2.4m with anti-climb features is the minimum. Most commercial and industrial sites use 2.4m as the default security height. Heights above 2m may require planning permission.

D-section pales are the standard profile — they are difficult to grip from the outside but relatively easy to manufacture. W-section (or corrugated) pales offer higher security as they are even harder to grip and more resistant to being bent or spread apart. W-section is specified for high-security applications such as prisons and military installations.

Standard post centres for palisade fencing are 2.75m. This suits standard rail lengths and provides adequate structural support. For high-security installations or exposed sites, centres can be reduced to 2.5m. Posts are typically RSJ (I-beam) section: 102×44mm for standard general-purpose fences up to 2.4m, stepping up to 127×76mm for taller 3.0m and 3.6m higher-security runs. Always confirm the post size against the manufacturer's system for your fence height.

Anti-climb palisade uses features that prevent climbing: triple-pointed pale tops, one-way security bolts (non-return), pale-to-rail fixings on the secure side only, and no horizontal footholds. The pales should be smooth D or W-section. Some specifications also require anti-dig measures such as extending the pales 300mm below ground.