I know at the end of my first blog I had said that next I would discuss how to achieve certain style classics using different materials. However I have decided that we should first discuss the different materials available so as to have a better understanding of future discussions.
What types of tiles are there to choose from?
There are quite literally hundreds of different types of materials available in the design/ building industries that come under the material description of tiles. These materials range from vinyl to porcelain and even carpet, and then each of these materials has a sub group that is derived from the way in which the material is produced and its finished appearance.
For this article I will be discussing, what most of us would consider to be a tile when thinking of product used to renovate a bathroom. I will be speaking about these materials in open loose terms, so that you have enough information to help you decide what materials suite your needs without being overwhelmed by information.
Ceramic is the most common term used to describe a tile.
- A ceramic tile is a clay based product (typically red or white in colour)
- The clay is quarried, purified and then dried to create a powder (body slip)
- The clay is injected into a mold as dry powder then pressed at a moderate pressure rate and fired at a moderate temperature to create a bisque.
- The fired bisque (raw tile) is then screen printed with a pigment or pattern and a clear glaze (silica glass) is applied over the top.
- The tile is then re-fired causing the silica to melt and form a durable non-porous layer over the top of the pigment or pattern. The glaze can be either gloss, matt or textured.
Ceramic tiles are typically used as feature and wall tiles; however there are some ranges available that can be used on the floor in a domestic application. These tiles are softer and easier to cut and are generally cheaper to install. The higher porosity rate (more then 0.5%) of the bisque can make them less frost resistant and their PEI (The Porcelain Enamel Institute hardness scale, which ranges from softest 0 to hardest 5) rating is usually between 0 and 3 making them unsuitable for commercial flooring applications. Glazed ceramic tiles do not require any sealing or special maintenance.
There are two main types of porcelain tile, glazed and full-bodied (some times referred to as vitrified).
The first type of porcelain tile we will discuss is glazed. The process for manufacturing glazed porcelain tiles is similar to that of glazed ceramic tiles. The main difference is the raw clay materials, these materials are of a higher quality and are processed more thoroughly. This means that the dry powder (body slip) is more pure and of a higher quality than that of a ceramic tile.
The other point of difference in the manufacturing process is the press rate and the firing temperature. These are both much higher in the production of porcelain tiles than what they are in ceramic tiles. The result is a denser less porous tile (less than 0.5%) that is more robust and durable. As the porcelain bisque can be fired at a higher temperature, the finished glazed tile will usually have a higher PEI rating than that of a ceramic tile. This allows all glazed porcelains to be used for both floor and wall applications in domestic spaces as well as light commercial environments. Glazed porcelains are available in gloss, matt or external finish. Glazed porcelain tiles do not require any sealing or special maintenance.
Full-bodied porcelains are manufactured primarily the same as the glazed porcelain counter part; the difference is on the surface. As mentioned with a glazed product the colour or pattern is printed on to the surface of the tile and then covered with a glaze and fired.
In the production of full-bodied tiles, the colour and or pattern runs through the tile from front to back. This is achieved by mixing the required pigments in to the powdered clay (body slip) prior to the powder being injected into the mold. If there are multiple colours needed to generate the pattern then there will be an injection head dedicated to the that particular colour. Once the mold has been filled the powdered clay is pressed and then fired.
More common today are double charged or double pressed porcelains. This is a manufacturing process designed to lower production costs and has no impact on the quality of the porcelain. The process is the same only that instead of the mold being filled with the pigmented clay it is only half filled, and then the balance of the mold is filled with un-pigmented clay. These two layers are then pressed and fired. This process reduces the amount of pigment required and lowers the cost of raw materials.
Full-bodied and double charged porcelains come in three main finishes; the first is natural, as the name suggest this is the natural finish of the tile after firing and is best described as a matt finish. The natural finish can be mechanically polished creating a high gloss finish. Or there may have been a pattern in the mold that creates a texture suitable for external use.
Natural and external full-bodied or double charged porcelains do not require sealing or any special maintenance other than being cleaned after grouting with Lithofin Cement Residue Remover.
Some polished full-bodied or double charged porcelains may need to be sealed after installation, the sealant will usually last 7 to 10 years, dependant on use.
There are two main types of composite stone currently in the market place. The first is called Terrazzo and originated from Italy. It is a cement and natural stone blend, the most common stones used are quartz and marble. This product comes in three finishes polished, honed (matt) or external. The external texture can be created a number ways either by the application of an acid wash or through a mechanical process that removes the softer particles from the surface of the tile leaving behind the denser particles to create an uneven non slip surface. These tiles need sealing and ongoing care to maintain their appearance.
The second is reconstituted stone, this material is similar to Terrazzo in that it is a blend and available in multiple finishes. However the additional material used to create this product is a man made polymer. To my knowledge there is no external finish available in this product as the polymers can be damaged and degraded by prolonged UV exposure. Some suppliers will void their warranty on their product if used externally. This material generally does not require sealing or on going maintenance.
Natural stone as the name would suggest is a range or products that are created by nature. These materials are quite literally quarried as large blocks, the blocks are cut into slabs, the slabs are finished in the desired finish, polished, honed (matt) or external (acid washed or mechanical application), the slabs are then cut into the selected sizes.
One thing that most people don’t understand about stone is that its colour texture and pattern is completely random, this is the point of natural stone and is a characteristic that tile manufacturers spend a lot of time and money on trying to copy. In addition to its randomness natural stone will generally always have some sign of a filler that has been used to correct or strengthen the natural faults and defects in the stone. When done correctly this fill is finished in such a way that it blends with the texture of the stone and becomes part of the pattern, but it will never be invisible.
I acknowledge that there are many, many different types of stone in the world. However I believe that when considering natural stone tiles, it is easier to group them into four main types of stone.
Sedimentary stones are made up of two sub-groups of stone due to the basic way they are formed. The first is sedimentary stone from hot springs. This type of stone is more commonly know as Travertine. It is created when sediment settles on the bottom of a hot spring; this sediment has a very high lime content and over time turns to stone. Travertine characteristically has holes in it from where the hot air and water was forced up though the earths crust. This type of stone is usually sold filled and honed or filled and polished for internal use, but can be left unfilled for external application to create a more rustic appearance. The stone may also be cut in two different directions to create to very distinct pattern. Cross Cut Travertine is when the tiles are cute across the holes in the block and creates a blotchy pattern similar to blue cheese. Straight Cut travertine is when the tiles have been cut along the grain of the block this creates a lineal pattern as the holes are exposed down their length and create valleys and trenches.
The second is sedimentary stone (from what I refer to as still waters); this type of stone is more commonly known as Lime Stone and forms on the bottom of lakes, rivers and oceans. This stone is easy to identify as it typically has no direction to its pattern and has a homogenise appearance. On closer inspection it is not uncommon to see fossilised organic matter such as sea life and leaves etc.
Igneous rock is volcanic rock, known as lava when in its molten state. These types of stone include Basalt (known as Bluestone in Australia) and Granites. These stones are easy to recognise as they generally have no directional pattern. Basalt may have what is referred to as Cats Paw or Laval Flow where a section of the stone cooled quickly and trapped small air bubbles. This is not a defect but a natural characteristic of the stone.
Metamorphic / compression stones are stones that were once something else, usually a lime stone of some description. Through compression / pressure from the earth’s tectonic plates and exposure to heat from the earths core these lime stones change and re-minerlise to become marble. There are many marbles such as Emperador where it is visible to see elements of its Lime Stone past. There are also lime stones like Grey Tundra were it is visible that it has been exposed to some heat and pressure as veins have began to form and quartz deposits are starting to crystallise.
As a rule National Tiles recommends that all stone should be sealed and maintained using the Lithofin stone care product range. Natural stone is not a product conducive to a low maintenance lifestyle and does require on going maintenance.
Glass started out as a feature product used sparingly in bathrooms and as bands in splash backs. But has now become a true product in its own right, it is being used more and more for full walls in showers and as the sole product for kitchen splash backs.
Typically glass was manufactured in the shape and size desired and then painted on the back so that the colour showed through once glued to the wall. Today National Tiles has an exciting new range of glass mosaics that have been laid onto a porcelain base and back by our lifetime guarantee. The benefit of this is that the product is easier to lay particularly for DIY. This product was launched recently by National Tiles with an in store design kiosk that allows you to view over 3000 design options for both kitchen splash backs and bathroom features. The glass mosaics require no sealing or special maintenance, however it is recommended that the grout be sealed to maintain their appearance.
National Sales Manager
National Tiles Premium Range