What is Ceramic Tile?

Ceramic tiles are one of the finest coverings for walls and floors available today. Ceramic tiles are made from mixtures of clays, sands and other natural substances. The body of the tile is moulded into shape and then (most usually) glazed prior to being fired at extremely high temperatures in a kiln. The body or 'bisque' may be left unglazed depending upon its intended use.

Ceramic tiles are hard, strong, hygienic, easy to clean, non-combustible and fire resistant. Tiles can be glazed or unglazed and show an enormous variety in colour, offering infinite design opportunities for every space. They can be used in both internal and external projects.

Glazed Ceramic tile is suitable for the majority of wall and floor applications. The product has various technical properties, depending upon its exact manufacture.

Unglazed Ceramic tile is also suitable for many uses. Depending upon its type of manufacture and the raw materials used Unglazed Ceramic tile falls into two broad categories; Quarry tile and Porcelain.

Quarry Tile (also referred to as Klinker) is an unglazed product with good wear properties and tends to find use in many domestic and commercial environments. (See What is Quarry Tile? for more information)

Porcelain Tile can be glazed or unglazed. Unglazed porcelain tile production is probably now the fastest developing area in the tile industry, with tile product being manufactured for virtually every conceivable construction project.
(See What is Porcelain Tile? for more information)

What is Porcelain Tile?

Porcelain tile is an extremely hard wearing tile product which is now widely manufactured to various technical standards. On the whole, it is manufactured to higher, more exacting standards than glazed ceramic tile, resulting in a more physically robust tile.

Superior raw materials and advanced production techniques are used. The resultant product allows for its use in much more demanding environments, where a glazed ceramic tile would show wear and tear after a relatively short period of time.

Unglazed porcelain has no surface glaze, therefore no glaze to wear off the tile. For this reason, heavy duty, unglazed porcelain tile is now regularly specified in commercial projects subject to heavy trafficking.

Unglazed Porcelain provides the perfect solution for today's projects; where the most stringent technical performance is required to underpin cutting-edge design.

Note: Glazed porcelain tile should not be confused with unglazed porcelain; like glazed ceramic tile there is a glazed surface that can wear over time in heavily trafficked environments.

Caution! As with all tile production, there are varying degrees of quality of manufactured product available throughout the world today. The term Porcelain alone, is not a guarantee of a high quality tile. For this you must check its technical standards and its recommended usage.

What is Quarry Tile?

Quarry or 'Klinker' tiles are generally smaller format unglazed ceramic tiles. As such they have no surface glaze to wear and therefore can provide a higher degree of natural slip resistance.

Quarry tiles are generally used in environments that require a more traditional design or in areas that require a good level of wear; hence they are used in many commercial environments.

Quarry tile is generally a more absorbent product than Porcelain and in many cases requires a chemical sealant to prevent ingress of dirt.

Does tile product need treating?

This depends upon the type of material. Natural materials such as limestone, marble, slate, etc, generally require a treatment to protect them against staining, followed by an occasional top-up treatment depending upon the treatment used and the degree of trafficking the tile surface receives.

On the whole though, ceramic and porcelain product requires no treatment, other than a good cleaning regime. Polished porcelain is generally required to be sealed by the majority of manufacturer's, as the surface integrity is actually disrupted by the polishing process in the factory. The very highest quality polished porcelain does not require sealing, due to improved technology, unless it is to be used in extreme conditions.

What do the slip resistance ratings of tile actually mean?

This is a particularly contentious issue, as at present there is little guidance or recommendations regarding 'slip resistance' within the relevant British Standard.

To compound this, there is presently no worldwide standard test for slip resistance. Different parts of the world use different testsand show the results for slip resistance in different ways.

The following information is therefore intended as a guide to assist you in identifying your basic requirements.

Note: There are other factors involved in determining the specification for slip resistance. Click HERE to find out more.

The Tortus Test
This test can be carried out on dry and wet floors, although research has now discredited this test for its misleadingly high values on wet surfaces.

However, as a base guideline, a minimum value of '0.4' should be observed for a dry, shod foot.

The Pendulum Test
(Slip Resistant Value (SRV) using 4S rubber)

Please note: The boundary values between one criteria and the next are not significant in themselves, thus there is no major difference between a floor which has an SRV value of 24 and one which has an SRV value of 26. All one can say is that the latter has a slightly lower potential for slip than the former, but that both are likely to cause someone to slip.

The Ramp Test
There are two separate test methods.

1. The operator is barefoot and stands on a water lubricated ramp.
2. The operator is shod with rubber-soled boots and the lubricant is engine oil.

Barefoot test results are quoted as a letter rating, which relates to the ramp angle, as follows:
A = person slips between 12 - 18°
B = ..between.. 18 - 24°
C = ..between.. 24°>

Failure to achieve 12° means 'no rating' can be given.

Shod results are quoted as an R-value, which relates to the ramp angle, as follows:
R 9 = person slips between 3 - 10 ° angle of elevation
R10 = ..between.. 10 - 19 ° angle of elevation
R11 = ..between.. 19 - 27 ° angle of elevation
R12 = ..between.. 27 - 35 ° angle of elevation
R13 = ..upwards of... 35 ° angle of elevation

Please note: These values should not be taken to imply safe use when fixed on ramps at these angles. These are merely conditions of testing and the angles do not refer to conditions of use.

R9 is a very broad ranging category because it includes some quite slippery tiles as well as some with moderate slip resistance.

The barefoot test is commonly regarded as the most useful guide to barefoot slip resistance in the wet.

To Conclude
Values issued by manufacturers for slip resistance relate to the test results as supplied from the factory. These values may change during the lifetime of the tile as a result of the following factors:

•  Residues build-up from cleaning materials.
•  Body fat build-up in barefoot conditions.
•  Chemical exposure which can etch the tile surface.
•  Surface wear.
•  Application of sealants, waxes, correctly or incorrectly applied.
•  Poor cleaning regime.

It is important therefore to consider the conditions to which the tiles surface will be exposed after fixing and to be aware that the 'cleaning regime' is as important in maintaining the slip resistance of the floor, as the construct of the tile itself.

Suggested Values only for the main testing mechanisms of slip resistance.

Industrial solutions such as workshops and food preparation areas will require more heavily textured and slip resistant tiles. In such cases it will be necessary to seek the manufacturer's advice.

Click here for The full article of The Tile Association working group's paper on Slip Resistance.

Can tile product be kept clean?

Tile product, as with all other forms of flooring can be kept clean. What is important is that the correct product is initially specified, which is suitable for its intended purpose.

At the design stage, the key elements to consider when determining how the product is going to look and continue to look after installation and throughout the subsequent duration of its life time, are as follows:

1  The moisture resistance of the product.
Depending upon the manufacture and type of material, moisture resistance can vary significantly. Extremes of this are, for example, Terracotta - a product which often has a very low moisture resistance and requires the use of a sealing treatment and Ceramic tile and Porcelain Stoneware - a product that has an extremely high moisture resistance.

Moisture resistance is significant with regards to how easily product will show signs of dirt and staining.

2  The abrasion resistance of the product.
It follows that in areas of high foot traffic a tile product should be selected with very high abrasive resistance. If not, the integrity of the surface can deteriorate, resulting in a less than satisfactory look.

Therefore the performance of the product is vital in maintaining its appearance.

3  The stain resistance of the product.
The stain resistance of glazed tile is on the whole excellent, although this will largely depend upon its abrasive resistance. Highly moisture resistant unglazed product, such as much porcelain stoneware has excellent stain resistant properties.

Stain resistance for natural materials is improved by the use of sealing treatments, though the cleaning regime thereafter is generally still more important than for glazed and highly moisture resistnat unglazed product.

Cost over Time
At the design stage one of the key considerations to be made is the degree of ongoing cleaning and maintenance requirements. If additional expenses are likely to be incurred in the subsequent cleaning and maintenance schedules, these should be taken into account at the concept stage.

The selection of a more expensive and wholly suitable product may well prove to be the correct financial choice against a less expensive, inferior selection that requires a high level of cleaning and maintenance.

Ceramic tile product has a significant advantage over other wall and floor finishes in that it can be readily maintained in a clean and hygienic condition.

For a full review of 'The Cleaning of Ceramic Tiles' please see The Tile Association article.

In areas where hygiene is paramount, is tile a suitable finish?

Wall and floor tiling in food preparation, treatment and processing areas is a suitable finish.

The Food Safety (General Food Hygiene) Regulations 1995, implementing the requirements of the EC Food Hygiene Directive, requires:

•  Walls, floors and surfaces in contact with food should be maintained in a sound condition and be easy to clean, and where necessary, disinfect.
•  The use of impervious, non-absorbent, washable and non-toxic materials.
•  Floors should be slip-resistant and walls should be smooth up to a height appropriate for the operations.

The regulations however, allow the risks to food safety to be taken into account in the application of these requirements:

•  In low risk areas, for example, materials with some absorption may be acceptable. (This should be confirmed with the food hygiene authority at the design stage.)  

Ceramic tiles, correctly specified and maintained provide;
•  A durable, attractive, hard-wearing and slip-resistant surface.
•  All the necessary requirements of the Food Safety Regulations 1995.

Furthermore, ceramic tile is also suitable wherever the specification requires a hygienic environment, e.g. food storage areas, canteens and restaurants, hospitals and industrial clean areas.

The main considerations are that the correct tile should be selected in accordance with the service conditions of the installation. Slip-resistance, durability and resistance to wear are all factors to be considered in accordance with the recommended specifications for adhesive materials and methods of fixing.

For more information regarding 'Ceramic Tiling in Food Preparation Areas' please see The Tile Association article.