Porcelain Tiles - A Simplified Overview

Porcelain Tile Myths

Firstly, let’s dispel a little myth; porcelain and ceramic tiles are not different. In fact, both are produced from ceramic, so essentially they are both types of ceramic tile.

The English word ‘ceramic’ is derived from the Greek word ‘keramikos’, which in turn comes from ‘keramos’ or ‘potter’s clay’. The prefix ‘ker’ means heat, fire or burn in Indo-European. As you would expect, words have alternative derivations in many ancient societies - fired loam, earth or clay to produce pottery.

What Is A Porcelain Tile?

Porcelain is one particular type of fired clay, albeit of a more refined quality than those used in ancient times. Kaolin clay (kaolinite) is the main component of porcelain tiles, although other minerals such as feldspar and quartz are present.

In British Standard terms, BS EN 14411 defines a porcelain tile as a ‘ceramic fully vitrified tile with water absorption of 0.5% or less’. In addition, traditional European porcelain tiles are produced with clays containing as little iron oxide as possible to produce a material as white as feasible.

When clay is fired, it is the degree of vitrification (from Latin ‘vitreum’), which determines whether a tile fulfils the requirements of a porcelain tile.

Vitrification is the transformation of a material into ‘glass’, which is formed during the high-temperature firing phase of tile production. The glassy materials produced fuse together forming a vitreous mass with a reduced number of pores, which is extremely hard and dense.

The Properties

The properties of porcelain tiles make them ideally suited to a wide range of applications. They are hard wearing, tough and strong; they absorb extremely low levels of water and are resistant to a wide range of chemicals.

These important attributes are essential for external use where they are exposed to extremes of weather (heat, rain, frost) and de-icing chemicals during the winter months.

Benefits of Porcelain Tiles

The durability of a porcelain tile helps reduce the environmental impact of the floor or wall finishes, as correctly selected and installed tiles will outlast many alternative finishing materials – an important factor to consider in today’s ‘green environment’.

Continuing with the environmental message, porcelain tiles are extremely good conductors of heat, making them an ideal surface for use with energy efficient underfloor heating systems.

In addition, their impervious surface allows for easy maintenance, especially in areas where cleanliness is of paramount importance, such as commercial kitchens, hospitals, WC areas and factories.

How To Lay A Porcelain Tile

As porcelain tiles have extremely low water absorption, there is little opportunity for a tile adhesive to gain a ‘hold’ within the pores. The mechanism for bonding in such systems is largely an adhesive bond, as a mechanical key is not really possible.

There may be some slight mechanical action where the tile has a profiled back but essentially an adhesive needs to ‘stick’ to the rear surface of the tile.

In reality, only polymer-modified adhesives will be suitable to bond to this surface, which in general will mean an adhesive classified as C2 in accordance with BS EN 12004.

Our Suitable Adhesives

From the Mapei range of products, adhesives such as Mapeker Rapid-set Flex or Keraquick would be appropriate materials for bonding porcelain tiles to a wide range of substrates, both internally and externally. For fixing to walls, Adesilex P9 or Keraflex Maxi S1 will provide the necessary grab and bond strength.

Where weight is an important issue, an adhesive from the Granirapid, Keraquick and Latex Plus.

In Summary

In summary, a floor or wall sporting a porcelain tiled finish will give many years of functional, durable and attractive service.

It will also benefit the environment, not only in terms of longevity but there are also many health benefits: A porcelain tile gives an easy to clean and keep clean finish, is non-porous so will not absorb dirt or bacteria, emits extremely low levels of VOC (Volatile Organic Compounds) and, when used as part of a heated floor, conducts heat very effectively.

By Colin Stanyard, Ceramic Product Manager, Mapei UK Ltd

Editor’s note:

Founded in 1937, Mapei is the world-leading manufacturer of adhesives and chemical building products - and a specialist in the production of adhesives and preparation products for the installation of wall and floor coverings.

Its extensive product range includes products for the preparation of all types of substrates used in construction. This includes surface membranes, levelling compounds, primers, waterproofing, ready mixed mortars, special products for the repair of concrete, admixtures for mortar and concrete, adhesives for floor and wall coverings, ceramic tiles, natural stone, soft flooring and wood, grouts and flexible sealants, mortars and binders for the restoration of period buildings, resin flooring, soundproofing systems, protective finishes for exterior walls and special hydraulic binders for screeds.