UK brickwork looks straightforward until you try to set out an opening, calculate quantities, or match existing bond. Getting the dimensions and bond pattern right from the outset avoids awkward cut-bricks, visual discontinuities and — in loadbearing work — structural weakness at perpends.
UK Brick Dimensions
The UK standard brick has a work size (the actual manufactured dimension, allowing for production tolerance) of:
- Length: 215 mm
- Width: 102.5 mm
- Height: 65 mm
This is specified in BS EN 771-1: Specification for clay masonry units (the standard for clay bricks) and BS EN 771-3 (for calcium silicate bricks). Both standards define a format tolerance of ±3 mm on each dimension for the most common tolerance class.
The coordinating size adds a nominal 10 mm mortar joint to each face, giving:
- Length: 225 mm (215 + 10)
- Width: 112.5 mm (102.5 + 10)
- Height: 75 mm (65 + 10)
These coordinating dimensions are the numbers to use for setting out — walls, openings, reveals and piers should be multiples of 225 mm horizontally and 75 mm vertically wherever possible.
Courses Per Metre
With a 10 mm bed joint, each course occupies 75 mm of height. Therefore:
- 4 courses = 300 mm
- 1 metre height = 13.33 courses — in practice, 13 courses occupy 975 mm, so a 1 m lift requires a slightly thicker bed on the final course, or the spec should call up heights in 75 mm multiples.
A convenient rule of thumb: 4 courses per 300 mm, or 13 courses per 975 mm, rounding to 1 m with mortar adjustment.
Bricks Per m² and Cost
For standard-format brickwork you need about 60 bricks/m² for a single-skin (half-brick, 102.5 mm) wall and 120/m² for a one-brick (215 mm) wall, plus around 5% for cuts and waste. At 2026 prices, common facing bricks run £0.45–£1.20 each (£450–£1,200 per 1,000), so the brick material alone is roughly £28–£75/m² for a single skin; reclaimed and handmade bricks often exceed £1.50 each. Add mortar (about 0.02 m³/m²) and labour — a bricklayer lays roughly 500–600 bricks per day at £200–£300/day.
Mortar Joints
Two joint types govern the bond:
- Bed joint — horizontal joint between courses, typically 10 mm
- Perpend (perp) — vertical joint between bricks in the same course, typically 10 mm
Perpends should be plumb and aligned across alternate courses in most bonds. Continuous vertical joints (a “straight joint” or “stack bond”) are structurally weak and should be avoided in loadbearing work unless reinforced.
Principal Bricklaying Bonds
A bond is the pattern in which bricks are laid to ensure perpends in adjacent courses do not align (which would create a plane of weakness). The most common bonds in UK construction are:
Stretcher Bond
The standard bond for half-brick-thick (102.5 mm) walls — cavity wall outer leaves, partition walls, and facework. Each course shows only the stretcher (long face) of the brick, offset by half a brick (112.5 mm) from the course below. It is the simplest and most economical to lay.
Bricks per m²: approximately 60 bricks (including waste allowance of ~5%).
English Bond
Alternating courses of headers (brick laid across the wall, short face showing) and stretchers. Produces a strong one-brick-thick (215 mm) solid wall. Once the standard for loadbearing brick construction before the cavity wall became dominant. The header course ties the two-wythe thickness together without separate ties.
Bricks per m²: approximately 120 bricks (one-brick-thick wall, both faces combined).
Flemish Bond
Each course alternates a header and two stretchers, giving a richer decorative appearance than English bond. Structurally comparable but slightly weaker than English bond because headers and stretchers appear in every course rather than alternating complete courses. Common on Georgian and Victorian domestic facades.
Bricks per m²: approximately 120 bricks (one-brick-thick), same as English bond.
English Garden Wall Bond
Three or five courses of stretchers between each course of headers. Faster and cheaper than full English bond, used where the full wall thickness is not needed for strength. Common on boundary and garden walls.
Header Bond
All bricks laid as headers. Used for curved work (the short dimension eases the curvature) and decorative detailing.
Bricks and Bond at a Glance
| Bond | Wall thickness | Bricks/m² (face area) | Typical use |
|---|---|---|---|
| Stretcher | 102.5 mm (half-brick) | ~60 | Cavity wall outer leaf, partitions |
| English | 215 mm (one-brick) | ~120 | Loadbearing solid walls, retaining |
| Flemish | 215 mm (one-brick) | ~120 | Heritage facework, Georgian style |
| English Garden Wall | 215 mm (one-brick) | ~80–100 | Garden/boundary walls |
| Header | 102.5 mm (laid across) | ~85 | Curves, decorative panels |
Figures include approximately 5% cutting waste. For a project order, add a further 5% contingency for damaged bricks and future repairs.
Setting Out Openings
Window and door openings should ideally be set to brick multiples: an opening width of 900 mm (4 × 225 mm) gives a clean stretcher bond return with no awkward cuts. Non-modular openings force cut closers and can disrupt the bond across the elevation.
At reveals (the return face of an opening), a queen closer — a brick cut in half along its length (roughly 51 mm wide) — is used to maintain the bond at the corner. Queen closers are placed next to the quoin (corner) header, not at the end of the course.
Mortar Specification
Mortar mix affects bond strength and durability. For facing brickwork on external cavity walls, a designation (iii) mortar — 1:1:6 cement:lime:sand — is standard for most applications. Designation (ii) — 1:0.5:4.5 — is used below DPC level, in exposed locations or for engineering brick work. Over-strong mortars (designation i) with high cement content can cause brick spalling by constraining thermal and moisture movement.
Mortar should comply with BS EN 998-2: Specification for masonry mortar. Pre-mixed retarded mortars are widely used on site for consistency; their working time (typically 36–72 hours) must be observed.
UK Standards
- BS EN 771-1: Clay masonry units (bricks)
- BS EN 771-2: Calcium silicate masonry units
- BS EN 998-2: Masonry mortar
- BS EN 1996-1-1 (Eurocode 6): Structural design of masonry
- BS 8000-3: Workmanship on building sites — masonry
Approved Document A (Structure) of the Building Regulations references Eurocode 6 and its National Annex for loadbearing masonry design. For straightforward domestic work, the deemed-to-satisfy tables in the document cover most standard situations without a full structural calculation.
