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Confused about 'rectification', or unfamiliar with terms like 'back buttering'? Whatever your existing knowledge, this is a layman-friendly guide to all terms tiling related.

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Calcium Sulphate (or Anhydrite) Screeds

Calcium sulphate dihydrate, also known as gypsum, is used as an alternative to cement/sand mortar screeds, especially over underfloor heating systems.


Produced with red, brown or white clay, these tiles are softer and less dense meaning they are easier to cut, drill and ideal for wall applications. Due to their high water absorption, ceramic tiles are always glazed.

Coefficient of Friction

A number used to describe the slip resistance of a tile: the higher the number, the greater the slip resistance.

Coefficient of Thermal Expansion

An indication of the extent to which a rise in temperature will cause a tile to expand.

Colour Gamut

The complete range of colours reproducible from a printing system on a specific substrate.

Coloured Grout

A commercially prepared cementitious mix used for filling joints between tiles. Colourfast pigments are added to Portland cement, aggregate, plasticisers, and water-dispersing agents. When set, the grout offers an attractive coloured finish to complement, or contrast with, the tiles.

Continuous Compaction

The production of gauged porcelain panels, often referred to as slabs, is results from this innovative compaction technology that allows the manufacture of XXL tiles in a wide size and thickness range.  Rather than vertical presses and trays, with a continuous compactor the clay body powder is deposited on a belt, carried inside the press beneath an upper belt, where the combined action of the two belts and two compaction rollers between non-deformable containment buffers, operating at extremely high pressure (around 400 bar/sq. metres) creates the flat green sheets ready for decoration and subsequent firing.

Cushioned/ Pillowed

The straight edges of a tile have been rounded and softened.


Curvature describes the extent to which an object, such as a ceramic tile, deviates from being flat.  BS EN 14411 details and defines the maximum permitted deviation from surface flatness, such as centre curvature and edge curvature, for each type of ceramic tile.

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