Ceramic Wall and Floor Tiles
Ceramic tiles are available in what seems like almost endless variety. To make the right choice it’s important to know about the different types of tiles and the uses to which they’re suited.
Ceramic tiles are not by any means a modern invention; baked and decorated clay tiles have been found in the remains of ancient civilisations going back as much as 5000 years. But whereas these early tiles were hand-made and of irregular shape and thickness, modern technology has given us perfectly-matched tiles by the million.
Ceramic tiles are mostly used on walls to provide a tough, maintenance-free and long-lasting surface finish. Cool to the touch (a boon in summer, but likely to cause condensation in winter), ceramic tiles are waterproof and stain-resistant, and can cope with reasonable extremes of temperature. As a result they are widely used in bathrooms and kitchens.
Floor tiles, on the other hand, are often used in other areas of the house. Virtually any floor in the house, and even the patio outside, can be tiled provided it is strong enough to support the weight of the tiles. Like wall tiles, they require very little maintenance apart from occasional washing, but they are much tougher and will withstand endless wear without showing signs of deterioration.
What is a tile?
The first stage in making ceramic tiles involves mixing together china clay and ball clay, sand, limestone, water (and sometimes recycled broken tiles) into a runny mixture called a ‘slip’. The water is then filtered and pressed out to leave a powder which is dried at over 500°C and can then be stored until required.
This powder is eventually compressed into tile shapes under great pressure. A frier removes any moisture and then a high temperature kiln is used to bake or fire the tiles for up to 30 hours at temperatures approaching 1150°C, fusing all the particles into what is known as a ‘biscuit’.
The next step is the application of the surface ‘glaze’ (not applied to unglazed quarry’ floor tiles). A variety of minerals is mixed together dry and is then heated to form a substance which looks like molten glass, called ‘frit’. At a later stage, china clay is added with even more ingredients. Dry colours are mixed too, if needed; these are also melted, then added to the frit, ready for application to the tiles.
For a plain colour, the biscuits pass twice through a liquid curtain of glaze. Textured and embossed effects are produced by spraying on the glaze, and designs are usually applied by a silk screen printing process. Finally the tiles are again fired at high temperatures to harden the glaze.
Shapes and sizes
Square tiles are the commonest, but many other shapes are available. Rectangular tiles can be used to achieve attractive effects, as can hexagonal or octagonal ones or interlocking Provençale shapes. Mosaics are available in a similar range of shapes.
Apart from the very small individual tiles which make up a sheet of mosaics, the smallest tiles available are 108mm (4-1/4in) square; these are generally for wall use. The sizes range up to 300mm (12in) square ones used on floors. In between you may find 152mm (6in) squares, 108x216mm (4-1/4×8-1/2in) rectangles, 200mm (8in) and 250mm (10in) squares. Thicknesses vary from 4mm (just over 1/8in) for the smaller wall tiles to 6mm (1/4in) for larger ones and up to 9.5mm (3/8in) for floor tiles.
Ceramic tiles can also be categorised by the kind of job they do in the overall tiling scheme. Some tiles are glazed only on their faces; they are called fieldrun tiles, and have their edges concealed when fixed. Many tiles have lugs built into the unglazed edges for keeping the tiles correctly spaced apart, and these are known as spacer tiles.
When tiling round window reveals, external edges or when finishing halfway up a wall, you need tiles with one or two glazed edges, and these are known as edge tiles or border tiles. REX (one rounded glazed edge) tiles used to be commonly available for this purpose but have now been superseded by the universal tile, which (usually) has all four edges glazed and serves as both a field and edge tile. This means you can use just one type of tile, avoiding having to work out how many edge or double edge tiles will be needed. However, the terminology can vary among manufacturers; with at least one brand, a ‘universal’ tile is one which is glazed on two adjacent edges and has spacer lugs on the other two, unglazed, edges.
Colours and patterns
Ceramic tiles are available in a wide range of colours and patterns and with smooth or textured surfaces. Many tile ranges now include both plain and patterned tiles in matching colours so that a surface can be tiled using a mixture. The patterned tiles can be placed in blocks surrounded by plain ones; they can act as a border, or they can be randomly positioned.
Not all tiles have a complete pattern on each tile. Many are intended to be placed in squares or strips, with individual tiles making up part of a larger design. Tile shapes can, in addition, be mixed to form a pattern: for example, a square tile of one colour can be surrounded by four octagonal tiles of another colour.