Brick choice matters more than most people realise. Use a soft common brick below DPC and it will spall within a decade; use a premium hand-made facing where common-stock bricks would do and you inflate costs by 40 % unnecessarily. The three broad categories — facing, engineering and common — differ in compressive strength, water absorption and frost resistance, all of which are defined under BS EN 771-1:2011+A1:2015 (specification for clay masonry units).
The standard UK metric brick is 215 × 102.5 × 65 mm (L × W × H). With a standard 10 mm mortar joint this gives a repeat module of 225 × 112.5 × 75 mm, meaning 60 bricks per m² in half-brick (102.5 mm) stretcher-bond walling.
Facing Bricks
Facing bricks are manufactured for visual quality: consistent colour, texture and arrises (sharp edges). They are not necessarily stronger than commons, but they are selected and graded for appearance. Facing bricks must declare their compressive strength, water absorption and freeze-thaw durability class to BS EN 771-1.
Durability designations under BS EN 771-1:
- F2 — Severe (fully frost-resistant): suitable for all UK exposures including capping, copings, below DPC, parapets
- F1 — Moderate (limited frost resistance): suitable for above-DPC walling in sheltered or moderate exposure
- F0 — Passive (no declared frost resistance): internal use only
Most modern UK-made wirecut and extruded facing bricks are rated F2. Handmade or ‘stock’ bricks vary — always verify the data sheet. For external applications in the UK, specify F2 as a minimum.
Water absorption designations:
- W2 — Low absorption (< 7 %): denser, better rain resistance
- W1 — Moderate (7–12 %)
- W0 — No declared limit
Engineering bricks are always W2; facing bricks range across all three classes.
Engineering Bricks: Class A and Class B
Engineering bricks are defined in BS EN 771-1 by their compressive strength and water absorption, not by visual quality. The old British Standard categories (BS 3921, withdrawn 2011) are still widely used in specifications but now correspond to declared performance levels:
| Property | Class A (former BS 3921) | Class B (former BS 3921) |
|---|---|---|
| Compressive strength | ≥ 125 N/mm² | ≥ 75 N/mm² |
| Water absorption | ≤ 4.5 % | ≤ 7 % |
| Frost resistance | F2 | F2 |
| Durability class | W2 | W2 |
| Typical colour | Blue-grey (Staffordshire blue) | Red or blue |
| Cost per 1,000 (2026) | £850–£1,100 | £600–£850 |
Engineering bricks are specified for:
- Below DPC and in ground — manholes, inspection chambers, retaining walls, sewer structures
- Parapets and copings — high-exposure locations where freeze-thaw and driving rain are severe
- DPC courses — two courses of Class B engineering brick act as an integral DPC in traditional masonry
- Exposed piers and gate posts
- Industrial floors — Class A in acid-resistant jointing compound
For most domestic drainage and below-ground work, Class B engineering brick suffices. Class A is specified where chemical resistance or very high compressive loads are required (manholes, bridge abutments, sewage treatment).
Common (Stock) Bricks
Common or stock bricks are produced for structural use where appearance is secondary — they will be rendered, plastered, or hidden. In London and the South-East, ‘London stocks’ (yellowish, handmade appearance) have traditionally been used as common bricks and are also used decoratively in restoration work. Flettons (pressed commons from Peterborough clay) were the dominant UK common brick from the 1900s to 1980s.
Common bricks vary widely in quality. They should not be assumed to be F2 — many are F1 or even F0. Never use unspecified common bricks below DPC or in exposed positions without confirming the durability class from the manufacturer’s data sheet.
Typical compressive strengths range from 15 to 50 N/mm², adequate for low-rise domestic loadbearing walls. Mortar designation should be matched to brick strength (weaker brick = softer mortar to allow differential movement).
Bricks Per m² and Buying Guide
| Bond | Brick thickness | Bricks/m² | Mortar/m² (approx.) |
|---|---|---|---|
| Stretcher (half brick) | 102.5 mm | 60 | 0.022 m³ |
| English bond (one brick) | 215 mm | 120 | 0.043 m³ |
| Flemish bond (one brick) | 215 mm | 120 | 0.043 m³ |
Add 5 % for cutting waste (10 % for complex patterns or curves). Bricks are sold per 1,000 or per pallet (typically 400–500 bricks depending on type).
2026 Cost Comparison
| Brick Type | Typical Cost/1,000 ex-VAT | Notes |
|---|---|---|
| Common / stock | £280–£450 | Flettons at lower end; London stocks higher |
| Wirecut facing — mid range | £350–£600 | Most common domestic choice |
| Handmade / tumbled facing | £650–£1,200+ | Conservation, match-to-existing |
| Engineering Class B | £600–£850 | Red or blue |
| Engineering Class A (blue) | £850–£1,100 | Staffordshire blue, heavier delivery |
| Reclaimed stock / London stock | £500–£1,000 | Variable quality — check frost rating |
Prices are trade ex-yard, London/South-East. Delivery typically adds £80–£180 per pallet. One pallet covers roughly 6–8 m² in stretcher bond.
Matching Existing Brickwork
Matching existing bricks for extensions or repairs is one of the hardest tasks on a renovation. Key variables are:
- Colour and texture — fire your architect or supplier a photo in daylight alongside a tape measure
- Dimensions — pre-1970 imperial bricks are 9 × 4.5 × 3 in (229 × 114 × 76 mm); modern metric = 215 × 102.5 × 65 mm. Mixing sizes requires adjusting joint widths
- Frost class — reclaimed bricks are often ungraded; assume F1 unless tested
- Mortar — matching the original mortar strength is as important as matching the brick colour
For listed buildings and conservation areas, your local authority’s conservation officer may specify approved brick suppliers.
Key Standards
- BS EN 771-1:2011+A1:2015 — Specification for masonry units: clay masonry units (defines F0/F1/F2 and W0/W1/W2)
- BS EN 772-1:2011+A1:2015 — Methods of test: determination of compressive strength
- BS EN 1996-1-1 (Eurocode 6) — Design of masonry structures
- BS 8000-3:2001 — Workmanship on building sites: masonry
- Building Regulations Approved Document A — Structural requirements for loadbearing masonry
[!warning] Reclaimed brick caution Reclaimed bricks are popular for their character but carry real risks. Many pre-1970 bricks were never F2-rated, and a decade of salvage yard storage does not improve frost resistance. Use reclaimed bricks above DPC in sheltered positions only, or obtain a test report (BS EN 772-22 freeze-thaw test) before specifying below DPC or in parapets.
