Concrete vs clay brick slips: what to compare before you choose

Brick slips give a wall the look of brickwork without building a brick wall. They are made from two main materials: fired clay and pigmented concrete. Both can look convincing; the differences that matter on a project are in size, weight, corners, colour and documents. This guide compares them on what you can actually check.

What each one is

• Clay brick slips are fired ceramic. Some are cut from facing bricks; others are made as thin units in their own right.
• Concrete brick slips, such as Ristone’s, are cast from concrete pigmented through the mix, in moulds that give the face and texture.

Standards and documents

In Zi 8/2015, Michael Ruppik of the Institut für Ziegelforschung Essen described the standards situation for ceramic brick slips at that time. He reported no dedicated product or application standard for brick slip cladding, described declarations using DIN EN 14411 and tests in the EN ISO 10545 series, including water absorption and frost resistance, and raised the alternative of deriving properties from EN 771-1 where a slip is part of a facing brick (Ruppik, Zi 8/2015). This is historical context, not confirmation of the current declaration basis for every clay slip. Ask for the current documents for the exact product.

For any slip, clay or concrete, ask which basis the declaration uses and which properties it covers. Our checklist of technical documents explains what to request.

Size and weight

Ristone’s four main concrete slips, from the product data:

Model	Size	Thickness	Corner piece
Oxford	240 × 73 mm	13 mm	no
Berlin	240 × 65 mm	10 mm	no
Belgrad	245 × 65 mm	15 mm	one-piece
Ribe	285 × 60 mm	15 mm	two-part

For these four models only, the historical box weights and pieces per box give roughly 15 to 24 kg per m² of wall with a 10 mm joint. The calculation is (box weight ÷ pieces per box) ÷ ((length + joint) × (height + joint)), with dimensions in metres. It excludes adhesive, joint mortar and corners. Berlin is approximately 14.71 kg/m², Belgrad 22.75–23.63 kg/m² (52–54 pieces per box), and Ribe 17.53 kg/m². Oxford gives 16.51 kg/m² from the recorded figures, but its current box contents must be confirmed in the quotation; confirm the current packing and weight in the quotation for each model. For a clay slip, ask the supplier for the weight per m² of the exact product and compare like with like, especially over external insulation.

Corners

On piers and outside corners, a dedicated corner piece gives the look of a whole brick turning the corner. For a clay range, ask the supplier which corner pieces are available for the exact product. In Ristone’s concrete range, Belgrad has a one-piece corner and Ribe a two-part corner. Without corner pieces, ask how corners are finished.

Colour

Ask the clay slip supplier how the chosen finish is produced and which variations to expect. Ristone concrete slips are pigmented through the mix. Ristone notes that small shade differences between production batches are possible, so order the full quantity for one elevation in one go and choose from a physical sample.

Fire rules on tall buildings in England

If the building has a storey at least 18 m above ground and contains dwellings, an institution or a room for residential purposes, regulation 7(2) of the Building Regulations 2010 requires materials in its external walls to achieve European Class A2-s1, d0 or Class A1, subject to the exemptions in regulation 7(3) (The Building Regulations 2010, regulation 7). The definition of a relevant building, including how the 18 m is measured and which storeys are excluded, is in regulation 7(4). Before specifying any brick slip on such a building, ask for the product’s classification document. Ristone confirms which documents exist for each product; nothing is assumed from a photo or a catalogue line.

How to choose

• you need a documented fire class for a tall building: start from the classification document, not the material;
• you have many piers or corners: choose a range with corner pieces;
• you clad over external insulation: compare weight per m² with the system’s limits;
• you want a specific colour across a large wall: choose from samples and order in one batch.

See concrete brick slips, work out quantities with our brick slips quantity guide, or send your project enquiry. For the UK, transport, customs duties and import VAT are paid by the buyer.