Tile Types5th February 2016
The range of tiles available today is almost endless, and will continue to develop. Below is a summary of the most common types of tile and a description of their properties and make up. Those most traditionally used are manufactured from raw materials to create a ’tile’ with a variety of performance and decorative characteristics.
Ceramic: A tile consisting of mixtures of clay, which are pressed and kiln fired at high temperatures, to give a hard ‘bisque or biscuit’. The ‘biscuit’ has a relatively high degree of absorbency enabling the adhesive to bond fairly easily. Ceramics may be left unglazed but are more often glazed to give more decorative options as well as physical benefits. This includes terracotta and quarry tiles. Ceramic tiles are generally not considered suitable for external use.
Vitrious (fully vitrified and semi-vitrified): Similar in manufacture to ceramic tiles, but incorporating different clays to provide tiles that are harder, denser and less absorbent. They may be fired for longer and at higher temperatures than ceramics. The term vitreous simply means ‘glass like’. The classifications for ‘fully vitrified’ is a tile with less than 3% water absorption. Fully vitrified tiles require the use of a polymer modified adhesive may be used externally in areas for spas and swimming pools. Semi-vitreous tiles have a water absorption between 3-7%.
Porcelain: Porcelain tiles are made from a different blend of clay, and a manufacturing process similar to ceramics. This controls shrinkage and water use and results in a very dense, hard-wearing tile with an absorbency of less than 0.5%, suitable externally for commercial projects as well as for swimming pools and areas subject to frost. ‘Full bodied’ porcelain doesn’t show wear as t here is no upper glaze. They are much more affordable and are nowadays also used in domestic installations.
Terrazzo: Either pre-manufactured or laid in-situ, terrazzo consists of granite and marble chips in a Portland cement, or sometimes epoxy resin binder. They can be polished to give a low absorbent and high strength tile suitable for commercial use.
Agglomerate: This type of tile is manufactured by mixing graded pieces of granite and marble with cement and resins to give a pre-formed tile. They generally have low absorption. These tiles are sometimes referred to as quartz. For use of these type of tiles with underfloor heating always consult the manufacturer for guidance.
Glass: Manufactured from glass, and available in many striking opaque colours. Traditionally manufactured in small sizes and often on mosaic backings, they are now available in much larger formats. They are very hard and offer extremely low porosity.
There are presently no British or European standards covering glass tiles so it is always worthwhile contacting the manufacturer for adhesive recommendations. Typically a minimum of a C2 classification is required but some decorative tiles may require resin based adhesives.
There is a wide variety of natural stones available today; all are cut from larger stones to make varied sizes and shapes with a host of characteristics. Always check with the supplier regarding a sealing product for use before and after grouting. Special care should be taken when dealing with resin backed stone.
Travertine: A form of limestone, travertine is very popular. It is a porous material and can be supplied with a good surface texture but can also be filled or honed to provide a smooth surface. Travertine should always be sealed before grouting. It is recommended to use a rapid set adhesive to minimise water absorption and potential staining.
Limestone: Available in a coarse or fine texture, and of varying strength, it is a porous material and should be sealed prior to grouting. It is recommended that a rapid set adhesive is used to minimise water absorption and potential staining.
Marble: Very durable and strong, available in a vast array of colours, due to impurities when being formed. Stronger than limestone and travertine, it is often supplied polished and sometimes cut down for mosaics. Although not as porous as limestone and travertine it is still recommended to seal prior to grouting.
Granite: Very strong stone suitable for heavy wear situations, that is resistant to most domestic use acids. It is porous and requires sealing before grouting. We recommend that a rapid set adhesive is used.
Slate: Very durable natural stone found in slabs that are split and then cut to size. Very hardwearing and offers a textured surface with a degree of anti-slip, making it ideal for external use. Slate, often supplied un-calibrated, should be sealed before grouting.