Classification of Ceramic Tiles

Once relegated to kitchens and bathrooms, the specification of ceramic tiles is now a viable alternative for any commercial application with its low maintenance quality and versatility.

Australian Standard AS 4662-2003 – which is identical to International recognized standard ISO 13006:1998(E) – defines ceramic tiles as:
“thin slabs made from clays and/or other inorganic raw materials, generally used as coverings for floors and walls. It further divides ceramic tiles into groups according to their method of manufacture and their water absorption.

We will look at the range and variety of product types that can be included in the classification of ceramic tile for floors and walls. The range of technical and aesthetic features and of the performances by the different types is vast.

The table below indicates the nine potential classes and the associated product standards. The greater the water absorption of the tile, the greater will be its expansion in damp or wet conditions.

Notes:
* Groups AIIa and AIIb are divided into two parts (Part 1 and Part 2) with different product specifications.
⁺Group BIII covers glazed tiles only. There is a low quantity of dry pressed unglazed tiles produced with water absorption greater than10% that is not covered by this product group.
⁺⁺These tiles are not covered by ISO 13006.

So what are the classification for type of tiles that we sell and use?

Porcelain (fully vitrified)
Either unglazed or glazed and characterised by a low water absorption of less than 0.5% (B Ia), porcelain tiles are normally dry pressed.

Vitrified and semi vitrified
These can either be unglazed or glazed and made by dry pressing or extruding. Such tiles fall into two main categories based on the water absorption of the tile body measured as a percentage.  Vitrified tiles Class BIb (dry pressed) and Class AI (extruded) have a water absorption of between 0.5% to 3%.  Semi-vitrified tiles Class BIIa (dry pressed) and AIIa (extruded) have a water absorption of between 3% to 6%.

Glazed porous body
The majority of standard wall tiles have glazed porous bodies with a water absorption between 10% and 20% and are classified BIII. When the face of such tiles is covered with a vitreous glazing either gloss or satin they are suitable for a wide variety of internal applications. Such tiles are not frost resistant and should only be used in internal conditions above sub zero temperatures.

Glazed vitrified
The porcelain vitrified and semi-vitrified tiles possess similar technical properties when glazed and can be used for internal cladding applications. Only vitrified and porcelain tiles with a water absorption value lower than 3% should be used for external cladding applications in conditions that are subject to frost.

Source: Australian Standard AS 4662-2003