Brick Pier Calculator — Bricks Per Course & Foundation Pad

A 1-brick pier (215mm square) uses 2 bricks per course, rotated 90° on alternate courses for bond. A 1.5-brick pier (327mm square) takes 4 bricks per course, and a 2-brick pier (440mm square) takes 6 bricks per course. These free-standing square piers are built with full bricks only (no cuts) around a hollow central void, which is filled with concrete once the mortar has hardened. Do not pour the concrete core too soon — wet concrete pushes outward and can blow the green mortar joints.

A brick pier needs a concrete foundation pad that extends at least 100–150mm beyond the pier on all sides. For a 1-brick pier, a 450mm × 450mm × 300mm deep pad is typical. The foundation pad must be on suitable bearing ground — compacted subsoil below topsoil depth. Use C20/25 (GEN3 designated mix per BS 8500-2) concrete as a minimum for garden-wall and pier foundations. See our Brick Calculator for the number of bricks needed.

Brick piers support gate posts, pergolas and fence panels, and stiffen freestanding garden walls. Per the Brick Development Association’s guidance, a single-skin (half-brick) freestanding wall above about 1m needs piers at no more than 3m centres plus at every end and corner. Pier size is keyed to wall height: a 1.5-brick (327mm) pier suits lower one-brick walls and a 2-brick (440mm) pier taller or more exposed walls. There is no single fixed height threshold — wind exposure and loading matter, so any loaded or tall pier should be designed to BS EN 1996 (Eurocode 6) by a structural engineer. For walls with openings, see our Lintel Sizing Calculator for the support above.

A 1-brick pier lays 2 bricks per course, turned 90° on alternate courses so the perpends never line up. A 1.5-brick pier lays 4 full bricks per course in a pinwheel, and a 2-brick pier lays 6 full bricks per course around its perimeter — both leave a hollow centre. The whole point of these stretcher-bond pier designs is that they use full bricks only, so no cutting is needed; the layout is simply rotated each course for interlock. Use engineering bricks for any part of the pier below DPC level, and fill the hollow centre with concrete (with rebar for gate posts) once the mortar has set.

Allow approximately 0.9 kg of prepared mortar per brick (bed plus perpendicular joints at 10mm), the same rate used by our mortar calculator. A 1-brick pier laying 2 bricks per course over roughly 13.3 courses per metre (75mm course height) is about 27 bricks per metre, so around 24 kg of mortar per metre of pier height. A standard 25 kg bag of mortar mix lays roughly 28 bricks. This figure is for the brickwork joints only — the concrete that fills the hollow centre of the pier is separate.