Glossary of Tile Material Types

Tiles are an excellent choice for a practical finish or a decorative feature when covering your walls and floors. They are stylish, durable and generally require minimal maintenance. Each type of tile has its own defining characteristics, whether natural stone, ceramic or porcelain this versatile floor and wall covering is available in a variety of colours, shades, sizes and textures. This guide will inform you about the different types of tiles and what to consider before you buy.

Stone types

Granite

Granite is a term referring to a range of Igneous rocks, formed deep below the earth’s surface through the slow crystallisation of molten magma cooling. It comprises of mineral grains, predominately quartz and feldspar, which can be seen with the naked eye.

Whilst there is no such thing as indestructible, granite is incredibly hard and durable; even in its natural state it is virtually impervious. Its colour and patterns vary through shades of white, pinks and greys. The vast array of mineral crystals that this stone is comprised of mean that there is a great variety of characteristics.

Limestone

Limestone is a sedimentary rock mostly formed during the Jurassic period, by the consolidation of sediments, seashells and other organic matter that collected on the seabed and compressed over time. These calcareous stones each exhibit individual colours and markings, also varying in density. Some degree of edge chipping should be expected along with occasional surface pitting, fossilised shells, fissures, mineral striations and resin fill.

Limestone often shows shells and other fossil patterns. It is available in an infinite range of shades – usually from cream through to yellow, but also encompassing white and black.

Marble

Geologically, marble is limestone which has been subjected to extreme heat and pressure, called thermal metamorphism, which changes the chemical make-up of the stone. This geological process leads to a dense, closed surface (albeit with some slight open veining or surface pitting) called recrystallisation, forming prominent veins and quartz in the surface of marble. The vivid colours vary depending on the prevalent minerals in the area from which it is quarried.

Marble is a very hard, dense and smooth stone, that readily lends itself to a polished finish, although it is also available in honed and tumbled finishes. It has been used in ancient buildings for millennia due to the myriad of colour tones and markings that are both beautiful and mesmerising to look at.

Sandstone

Sandstone is a sedimentary rock made up of compressed grains of sand, deposited by water or wind, and then bound together by a secondary mineral such as calcite, clay or silica. It is a hard, yet very porous stone. It is available in two finishes:

Riven – characterised by its granular, undulating surface

Honed – a smoother finish, with variation in texture and some edge chipping.

Sandstone is hard-wearing, frost-resistant and low-slip which makes it ideal for outdoors, especially in its large flag format.

Slate

Slate is a fine-grained metamorphic rock, derived from an original sedimentary rock made of clay or volcanic ash. It is a durable stone and it is available in a diverse range of colours and textures. It is made of parallel plates and is best known for its ability to be split into broad sheets. Riven slate can be used both internally and externally, and has a naturally cleft surface, with chips and chisel marks present on some surfaces.

The natural, slight undulations in the stone (caused by the way it is split when quarried) give it instant character. It is available in a range of dark shades, making it easy to maintain.

Terracotta

Terracotta is a type of ceramic tile made from natural clay, and its meaning is ‘baked earth’. The tiles are moulded, either by hand to give a more rustic feel, or by machine for a more uniform, consistent finish. The tiles are then kiln fired to bake the clay, producing a rigid product. All terracotta tiles will be subject to variation and edge chippings, contributing to the finished look of an authentic terracotta floor. As a kiln baked product, terracotta is a very porous material, and if left unsealed will give a very different look from a finished, sealed floor.

Travertine

Travertine is a crystallized form of calcium carbonate, or limestone, which is deposited by hot mineral springs. This method of formation creates a honey-combed structure, evident in the visible surface pits and voids when first quarried. It is generally available in vein-cut and cross-cut formats, depending on whether they are cut perpendicular or parallel to the long veins present. Once cut, they are often filled with colour-matching resin at source, giving the travertine a much smoother and more refined finish. Generally, the voids are only left unfilled in tumbled, brushed and splitface finishes, when they are filled at the tiling stage.

‘Nature’s masterpiece’, travertine has been a signature stone of Italian architecture from the Romans onwards. Especially when vein-cut, travertine has a full range of shades and natural pitting that give it a combination of character and sophistication. It is perfect for feature walls and chic interiors. There are variations in thickness and finish, as well as natural blemishes.

 

Tile types

Porcelain

Porcelain tiles are made from a type of ceramic (a mixture of clays and minerals) with a very low absorbency. They are fired at a very high temperature, resulting in an extremely hard-wearing product.

The majority of porcelain tiles are rectified, meaning there is little size variation within a production run. However, different batches may vary in size slightly, therefore it is always advisable to purchase all necessary tiles at the same time and avoid mixing sizes of these tiles. Due to the nature of the manufacturing process, porcelain tiles may be subject to a very slight ‘bow’ along the length of larger tiles (this can normally be corrected using a specialist clip system). This slight bowing, (which fall within European Standards) can cause slight ‘lipping’ between one tile and the next. This effect can be minimised by laying the tiles square, or staggered by not more than a third of a tile length, rather than laying brick-bond.

Porcelain that is ‘non-rectified’ may vary very slightly in dimension, which means that a slightly wider grout joint needs to be used. NB ‘non-rectified’ porcelain products always carry a calibre code in order that tiles can be grouped together by their finished size.

Encaustic

Encaustic tiles are cement tiles where the pattern or figure on the surface is a product of different colours of clay, rather than a glazed application. In this technique, the pattern is inlaid into the body of the tile so that the design and colour remain, even as the tile wears. Cement tiles will age naturally and develop their own patina with time, like natural stones, and are suitable for domestic and commercial use on floors and walls. There will be variance between individual encaustic tiles. Thickness can vary slightly from tile to tile, as can pigment shadings, and patterns may bleed at the edges when they are compressed, all enhancing their uniqueness. Another reason for their attraction is that they are a ‘living’ tile that changes over time. Encaustic tiles can be used on almost any internal floor or wall surface, providing the sub-base is suitable and prepared for tiling and weight-bearing because these tiles are a little heavier than the average wall tile. The tiles can be used in wet areas but it’s likely they will fade slightly, especially darker colours and patterns due to the natural pigments used. If the tiles are coated with a thin layer of sealer every one or two years this will reduce, however, it is all part of the natural ageing process. The tiles are not classed as frost resistant, so we do not recommend using them in external areas that are exposed to wet and freezing conditions. Please note this product requires sealing as part of the installation process.

Terrazzo

Terrazzo tiles are manufactured using the same technique as encaustic tiles, but ground marble chips are added to the top layer to add extra durability and visual effect. Please note this product requires sealing as part of the installation process.

Ceramic

Ceramic tiles are made of clay and generally fired at lower temperatures than porcelain tiles. These tiles are then glazed with a base colour and can be over-printed or hand painted with a pattern, in addition to a matt or gloss finish. Porcelain designs cover a large variety of styles, from those that mimic natural stone or wood, to minimalist architectural ranges. Unlike natural stone, ceramic tiles do not require sealing (with the exception of crackle glaze tiles) and are suitable for domestic floors (where specified) and walls.

Glass

Glass has its own beauty and can also be transformed by the natural or ambient light with sparkles, reflections and fascinating changes of colour. Available in both tiles and mosaics, they are made from silica fired at incredibly high temperatures and then coloured to offer beautiful pastel shades. Lighting is an especially important factor due to the opaque nature of glass. Since solid pieces of glass exhibit the same properties as any piece of glass, care should be taken particularly when cutting and finishing.  Glass tiles are easy to maintain and non-porous.