Glossary of Tile Terms
Our glossary of tile and tiling terms combines frequently asked questions with the jargon you’ll hear bandied around development building and renovation project sites. So, if you don’t know your mitred edges from your bevelled edges or your Calacatta marble from your Carrara marble, this comprehensive glossary is guaranteed to help. Do let us know if there is anything you’d like us to add.
Technically speaking, porcelain tiles are a type of ceramic with a water absorption rate of less than 0.5 percent. Porcelain tiles are crafted from pure fine clays and feldspar and then fired at higher temperatures than traditional ceramic tiles which causes the tiles to become vitrified, silica mixed with the clays turns to molten glass and bond the mixture together – this results in a finished product that’s extremely dense, durable and resistant to wear and water. Porcelain tiles are generally available as either full-bodied or glazed porcelain tiles.
Vitrification describes the process of making glass. Tiles become vitrified when they are fired at high temperature, causing the silica in the mixture to turn to glass. Vitrified tiles generally have a very low water absorption rating of below 0.5%. Porcelain tiles fall into this category and this is why they commonly referred to as vitrified tiles.
Using a high-temperature kiln to fuse the layers, ceramic tiles are made from clay and sand that’s ground to a fine powder with added water that’s compressed in a mould. Once dried, the clay/sand base is often primed and then painted or printed before a final glaze is added. More suitable as wall tiles or as floor tiles in low-traffic areas, ceramic tiles are often chosen for their decorative nature rather than their durability.
Encaustic tiles are ceramic tiles that are made by firing two or more (sometimes up to six) colours of clay. It’s these combined colours, inlaid into the body of the tile, that create the decorative effect, rather than paints or glaze. The firing together of two or more clays helps create a more stable and frost-proof tile that makes it good for all-round use.
Originally a way for the ancients to bring a slice of the outside in with mosaics of flora and fauna on their walls and floors, today we use mosaic tiles in the same way but stretch the boundaries with our choices of pattern, colour and tile shapes and sizes. Mosaic tiles are generally constructed using a combination of small glass, natural stone or ceramic tile pieces called tesserae, which make a pattern that either stands alone or can be laid next to other ceramic or porcelain tiles to create a larger pattern.
Natural stone tiles
The original building material, natural stone tiles are quarried in many varieties including: marble, granite, slate, sandstone and limestone. Each natural stone tile is unique and this has heaps of appeal for those looking for authenticity but this can come at a price – in terms of initial outlay and ongoing maintenance. There are many natural stone alternatives, some of the best being stone effect porcelain tiles which combine practicality and panache.
Renowned for its super-hard structure and low porosity, granite tiles are a popular choice for kitchens and outdoor areas. When sealed they also offer stain-resistance but, as with all natural stone tiles, this extra commitment to maintenance can be a step too far for those looking for easy-care tiles.
Made from naturally forming sedimentary rock, each limestone tile will have its own natural charms including neutral colour variations, veining, fossilisation and surface pitting. Natural limestone tiles and flagstones are a popular hard-wearing choice for kitchens and patios while limestone effect porcelain tiles, with their ultra-thin but equally strong structure, can be a popular practical choice.
The result of limestone undergoing high pressures in the earth’s crust, marble tiles have been a statement of opulence for thousands of years. Available in myriad colourways – from white and grey to black and silver – with varying depths of veining, marble tiles are highly sought-after but they are expensive to buy, install and maintain. This explains why many modern consumers choose marble-effect tiles made from porcelain and alike.
An exclusive Italian marble that’s white with grey veining, Calacatta marble generally has a pure white base with dramatic, dark patterning. Calacatta marble also comes in other varieties that combine different colourways, for example Calacatta Gold.
A more readily available Italian marble that’s mined from quarries in Tuscany, Carrara marble is white with subtler and more delicate blue-grey veining than Calacatta Marble. While more commonplace and a classic choice, this is still a luxury material and like all marbles requires higher level of maintenance than its man made alternatives, such as marble-effect porcelain tiles.
A coarse-grained sedimentary rock formed by compressed sand deposited by water or wind. It is commonly characterised by a granular surface. Sandstone is a hard yet very porous stone that requires thorough impregnation and surface sealing when used internally. Sandstone tiles in its large flag format are a very popular external choice.
As with marble, slate is a metamorphic rock that’s formed when shale is compressed over long periods of time. It’s extremely durable so it’s a popular choice for roof tiles and flooring but it’s also quite brittle and it’s very easy to cleave slate into thin sheets. Because of this, natural slate floor tiles may chip or split quite easily.
Slate is a fine-grained metamorphic rock that is characterised by its ability to be split into broad sheets. Slate is a durable stone which presents a diverse range of colours and textures. We offer ‘riven’ slate tiles, which have a naturally cleft surface and is rustic by its nature, with chips and chisel marks present on some surfaces. Some of our ‘riven’ slate varies in thickness or is ‘uncalibrated’ and therefore requires ‘bedding up’ with the appropriate thick bed adhesive during installation. We also offer ‘honed’ and ‘brushed’ slate tiles that are machined to create a smooth, even surface. Some of the dark honed slate can be prone to scratch marks.
The name terracotta translates from Italian as ‘baked earth’ and that’s essentially what terracotta tiles are – slabs of clay fired in a kiln. The familiar red, yellow and pink tones we associate with terracotta are due to the iron content present in the clay. Although terracotta floor tiles have been used for hundreds of years, they are quite porous and easy to stain.
Terracotta is made from natural clay which has been moulded and then kiln fired to bake the clay and produce rigid tiles. The clay is either moulded by hand, these tiles offer a more rustic feel, or machine-moulded for a more consistent finish. All Terracotta tiles will be subject to edge chipping and variation which is part of the finished look of an authentic Terracotta floor. Terracotta tiles, when untreated, are very porous and as such any unsealed tiles will look very different from your finished floor.
Travertine is created by hot mineral springs. Resulting in a honey-combed structure which when finished has visible surface pitting and voids. Travertine tiles are available in either ‘filled’ or ‘unfilled’ finishes. With an unfilled travertine tile the surface voids will be filled with grout during the installation process. Filled travertine tiles have had these pits and voids filled at source with a colour matched stone resin. Whilst this gives a smoother surface, through general usage, some small areas of fill may dislodge or previously unexposed holes may become visible. This is not unusual and the holes should be re-filled with a suitable resin or grout.
The name can be a bit misleading; unlike natural stone, quarry tiles don’t come from a quarry! Instead, ground raw materials are mixed together, ‘extruded’ into tile forms and then fired at high temperatures. The resulting quarry tiles are unglazed and extremely hard, which makes them suitable for a variety of floor areas. They’re also resistant to water so can be used outside, rather like our own large format porcelain tiles.
Slip resistant tiles
Slip resistant floor tiles provide extra grip underfoot, so they’re ideal for floors and wet areas where you may want extra peace of mind. The slip resistance of tiles can be measured by more than one method. The most accurate method is the PTV test, which rates tiles with a score out of 100 with a higher value donating a higher resistance to slip, and this is the method by which all Porcel-Thin tiles are measured. The Health & Safety Executive (HSE) recommends that tiles used for floors in public areas must haves a PTV slip resistance of 36 or greater. In order to test the slip resistance of a tile correctly it should be tested in dray and wet conditions and care should be taken when choosing slip resistant tiles to ensure that a particular tile offers the required level of slip resistance when dry or wet. Porcel-Thin provide wet and dry slip resistance test data for all porcelain tiles in our collections and offer PTV slip resistance testing in house.
Ideal for feature walls, split face tiles are made from textured strips of natural stone. These are cut to different lengths and thicknesses and pieced together to give a natural, handmade finish. Porcelain split face wall tiles are now available which offer more durability and performance in wet areas.
Splitface tiles are medium to large tiles that are made from smaller rectangular pieces of natural stone, normally slate or quartzite. The pieces are glued and butted together to make a single tile that does not require grouting. However this means they are only recommended for dry areas.
Bevelled edge tiles
A tile that has a subtle slope or slant down to a thinner edge. It helps to add more definition to a tile, and its angled edges help to bounce light around a room.
Wall tiles with a bevelled edge finish have a chamfered finish so the edges of the tile are slightly lower than the main body, to give a distinctive finish. Metro tiles are an example of a classic bevelled edge tile.