How many bricks do I need per square metre?

For a standard UK brick (215 x 102.5 x 65mm) with 10mm mortar joints, you need approximately 60 bricks per square metre for a half-brick wall (single skin, stretcher bond) and 120 bricks per square metre for a one-brick wall (double skin). Always add 5-10% for cutting waste and breakage.

What mortar mix should I use for brickwork?

For most domestic brickwork, use a 4:1 mix (4 parts building sand to 1 part cement). For below-ground work or retaining walls, use a stronger 3:1 mix. Adding plasticiser makes the mortar easier to work with. Approximately 1kg of mortar mix covers 0.014 m² of brickwork, equating to roughly 40-50kg of sand and 10-12kg of cement per square metre.

What is the standard brick size in the UK?

The standard UK brick size is 215mm long x 102.5mm wide x 65mm high. This is defined in BS EN 771-1. Including a 10mm mortar joint, the working size (also called the coordinating size) is 225mm x 112.5mm x 75mm. This coordinating size is what you use for calculating quantities.

Do I need Building Regulations for a garden wall?

Garden walls under 1 metre high adjacent to a highway, or under 2 metres high elsewhere, generally do not need planning permission. However, walls over 1 metre in height must comply with Building Regulations regarding structural stability. Retaining walls holding back significant earth loads should always be designed by an engineer.

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Complete Guide to Brickwork in the UK

Brickwork is one of the most enduring building traditions in the UK, with techniques and materials that have been refined over centuries. Whether you are building a garden wall, an extension or a decorative feature, understanding brick types, bond patterns and mortar mixes is essential for a structurally sound and attractive result.

Standard UK Brick Sizes

The standard UK brick dimensions are defined in BS EN 771-1 and have remained consistent for over a century:

Dimension	Actual Size	With 10mm Mortar Joint
Length	215mm	225mm (coordinating)
Width	102.5mm	112.5mm
Height	65mm	75mm

The coordinating dimensions (including mortar joints) are the figures used for calculating quantities. The key relationship is that one brick length (225mm) equals two brick widths plus one mortar joint (112.5 + 112.5 = 225mm), which allows different bond patterns to work correctly.

Bond Patterns Explained

The bond pattern determines how bricks are arranged in a wall. Each pattern has different structural properties and visual effects:

Stretcher bond is the most common pattern for half-brick walls (single skin). All bricks are laid lengthways (as stretchers) with each course offset by half a brick. This is the standard pattern for garden walls, internal partition walls and the outer leaf of cavity walls. It uses the fewest bricks per square metre and has the least cutting waste.

Flemish bond alternates stretchers and headers (bricks laid end-on) in each course. The headers in one course centre over the stretchers in the course below. Flemish bond creates an attractive decorative pattern and is commonly seen on older UK properties. It requires a one-brick (double skin) wall thickness.

English bond alternates entire courses of stretchers with entire courses of headers. It is the strongest bond pattern and is used for engineering brickwork, retaining walls and load-bearing structures. Like Flemish bond, it requires a one-brick wall thickness.

Mortar Mixes for Brickwork

The correct mortar mix depends on the application and the exposure conditions:

Mix Designation	Ratio (Cement:Sand)	Application
M6 (Class iii)	1:5 to 1:6	Internal walls, sheltered external walls
M4 (Class ii)	1:4	Most external walls, garden walls
M6 with lime	1:1:6 (cement:lime:sand)	Conservation, period properties
M12 (Class i)	1:3	Below ground, retaining walls, engineering

Plasticiser: Adding a liquid plasticiser (such as Feb-Mix or Everbuild Bricklaying Plasticiser) to the mortar makes it more workable and easier to lay. Use instead of washing-up liquid, which can weaken the mortar. Follow the manufacturer's dosage instructions.

Mortar Quantities

For standard 10mm mortar joints with a 1:4 cement-to-sand ratio:

Half-brick wall (stretcher bond): Approximately 0.02m³ of mortar per m² of wall. This equates to roughly 32kg of sand and 8kg of cement per m².
One-brick wall: Approximately 0.04m³ of mortar per m². This equates to roughly 65kg of sand and 16kg of cement per m².
A 25kg bag of sand covers approximately 0.8m² of half-brick wall.
A 25kg bag of cement covers approximately 3m² of half-brick wall.

UK Brick Types

The UK produces and imports a wide variety of bricks for different applications:

Common bricks: £250-£400 per 1,000. Used for general construction where appearance is not critical (below ground, behind render). Fletton commons are the traditional budget choice.
Facing bricks: £350-£800 per 1,000. Attractive finish intended for visible external walls. Available in hundreds of colours, textures and styles from manufacturers like Ibstock, Wienerberger and Forterra.
Engineering bricks: £400-£600 per 1,000. Dense, strong bricks with low water absorption. Used for below-ground work, damp-proof courses (DPC) and load-bearing applications. Class A (strongest) and Class B (most common) are specified in BS EN 771-1.
Reclaimed bricks: £500-£1,500+ per 1,000. Salvaged from demolished buildings. Highly sought after for matching existing brickwork on period properties and conservation areas. Prices vary enormously based on age, type and condition.

Building Regulations for Brick Walls

Under UK planning law, garden walls generally do not need planning permission if:

The wall is under 2 metres high (or 1 metre if adjacent to a highway)
The wall does not form part of a listed building or conservation area boundary

However, Building Regulations apply to walls over 1 metre that are structural, retaining significant earth loads, or forming part of a building. Key structural requirements include adequate foundations (typically 300-450mm wide, 450mm+ deep concrete strip), damp-proof courses, and appropriate wall thickness for the height.

Retaining walls: Any wall retaining more than 600mm of earth should be designed by a structural engineer. The lateral pressure from wet soil can be enormous, and inadequate retaining walls can collapse without warning, causing injury and property damage.

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