Water Absorption 101

Water absorption rates are the most important measurement of a tile. Water absorption measures how much moisture a specific type of tile is likely to absorb on an ongoing basis. Some types of tile may crack if the moisture penetration is too high. In general if the tile has a low water absorption, the durability and strength are increased. Low water absorption restricts the amount of water that may cause failure by cyclic salt attack and freeze thaw. The water absorption percentage reflects the density of the tile body. Water absorption is also directly related to the suitability for interior or exterior applications. For exterior applications, the selected tiles should have a low water absorption rate, especially in climates subjected to heavy rainfall and freezing and thawing cycles. A low water absorption rate also enables a tile to resist food or beverage stains.

Testing for water absorption determines the apparent porosity and relative density as a means to classify ceramic tiles according to the international standard ISO13006-10545/98. There are four categories:

• B2b. Non-vitreous - Low density, High water absorption of more than 6.0% (Ceramic)
• B2a. Semi-vitreous - Medium density, Medium water absorption of more than 3.0%, but less than 6.0% (Ceramic)
• B1b. Fully Vitrified - High density, Low water absorption of more than 0.5%, but less than 3.0% (Ceramic)
• B1a. Impervious - Extremely high density, Very low water absorption of less than 0.5% (Porcelain)

One thing to remember is that while porcelain is often viewed by the consumer as a superior product this does not guarantee that the material is fit for purpose, or put another way, it is unnecessary to use porcelain in an interior space with low traffic that is not exposed to extreme temperatures or water.

There are 3 methods to determine the water absorption of tiles:
Boiling method
Vacuum method
Electrical method

The boiling method is used to classify the ceramic tiles and involves drying the tiles out and then boiling them in water for 2 hours followed by cooling to room temperature over a four hour period. The mass of the tiles are weighed both before and after the water immersion to determine the percentage of water absorption.

The vacuum method evacuates the air from a chamber with the tiles inside and then immerses the tiles in water. Once again the tiles are weighed before and after water immersion to determine the apparent porosity, apparent relative density and bulk density.

The electrical method requires that the tiles be immersed in water for two hours then a high voltage electric current is passed through the tiles. The measured conductivity of the tile determines the percentage of water absorbed.

OK, those are the basics, take a look at our catalogues, select a few tiles and determine a suitable application. Ask your experienced staff to check or email us and we'll answer you.

10 Top Technology Tiles

Today I'd like to give you the heads up on some truly cutting edge technology in tiles. Humans have been producing ceramics for over ten thousand years, it is one of our most ancient industries, yet today the ceramic tile industry is experiencing a remarkable renaissance by integrating several cutting edge, hi tech innovations. In this post I will review ten extraordinary technologies that are transforming tiles.

These are all real technologies that are available in the market now. While many are hardly standard stock items you will easily imagine their application to specific architectural projects. Of course as the technologies become established prices will drop and these innovations will become more ubiquitous.

Above: LED glow tiles
These tiles are just amazing and I can certainly imagine them installed in a nightclub. The tiles are independently  pressure sensitive and can be programmed to display animated graphics on walls and floors. Available in a special dance floor format they are equipped with various gaming features as well!


Anti-pollutant & antibacterial air-cleaning tiles
In April I wrote about some tiles installed as cladding on a building in Mexico City that actually clean pollutants out of the air. How do they work? Titanium dioxide is fixed at a high temperature into microscopic particles in the glaze. When the tiles are exposed to sunlight or artificial light, the particles act as catalysts, which carry out an anti-polluting, antibacterial action most importantly extracting toxic Nitrogen Oxides (NOx) from the air. In practice, it is as if the floor or wall covering turns into a tree, breaking down polluting agents and bacteria, thanks to the mechanism that works just like chlorophyl photosynthesis. It has been demonstrated that 1000m2 tiles carry out the same function as 20 mature trees, in terms of reduction of NOx, so 50m2 = one mature tree and 25m2 = one medium-sized tree!

Thermally sensitive colour changing tiles
These have been around for a while. Hot water causes the thermally sensitive dye under the glaze to change colour. The base color of the tile can match almost any color, and the temperature change point can be set to the user’s environment and requirements. The dynamic color change begins at the selected activation temperature and shimmers through three phases, one with each 6–10° rise in temperature.


Personalised print-on-demand inkjet tiles
I wrote about inkjet technology in the last couple of weeks so I won't go into detail except to say that the technology means it possible to cost-effectively produce entirely unique custom designs including say the buyers own artwork. This really is the future and will become increasingly common.


Liquid tiles
The Liquifloor is a really innovative concept The tiles consists of layers of durable PVC. The top layer is transparent and below this is a coloured gel-like liquid, which deforms and flows so the design keeps changing with the change of pressure on the tiles.


LED dot tiles
These tiles are made to entertain.Kids will love them! These LED dot tiles are exceptionally beautiful and will completely light up your house even if without power. They glows in various colours when walked upon At night they can be programmed with figures and shapes One delightful feature is that they can be set to display different colours according to the weight of the person who’s walking on them!


Info display tiles
The I-Quad is an awesome concept in tiles which comes with various interactive features. The array is made of LED back lit tiles which are framed and can display date, time, weather, the latest affairs, buzzing news, e-mails, images and plenty more. The array is USB or Bluetooth enabled.


Hydrophilic self-cleaning tiles
The diagram is pretty self explanatory. These work with a combination of the Titanium dioxide anti-pollutant technology plus a nanotech surface texture that reduces water tension allowing rain to wash the down to a submicroscopic level.Self cleaning tiles will be a major boon for bathrooms, commercial catering spaces, other hygiene sensitive industries as well as building exteriors.

Photoluminescence & touch switches
Other glaze technologies include photoluminescence for energy-free safety or informational lighting systems without electricity, and glazes that act as touchscreens for unobtrusive electrical systems like lighting or alarms with no need for switches. The bath pictured here is tiled with 1,7cm mosaic tiles that absorb energy during the day and glow at night.

More next time!

"The glaze has failed." What do you say to your customer?

The customer complaint:

Being a natural product that is fired in a kiln, there will always be some tiles in each batch that show some imperfections. Before packaging, tiles are graded and any with visible imperfections are removed and sold as seconds. Nonetheless a few will always slip through the system. In some remarkable instances the glaze may have been improperly fired to the body of the tile but this is extremely rare in modern tiles. The photo above shows massive glaze failure on tiles from the exterior of a 90 year old building. This hardly ever happens today and I think we can all agree that the guarantee, if any, has long since expired. The cause in this case was massive moisture absorption from rain seeping into the substrate which after decades eventually caused the glaze to start popping off.

Much mor common are tiles with tiny strips of missing glaze on the edges. These tiles are perfectly sound, but all the same are imperfect. International standards allow 5% of any first grade consignment to have some visual imperfections, this means that 5 tiles in each group of 100 tiles may have some imperfections. The tiler should always put these tiles aside and use them when a cut tile is needed.

If a customer complains of a tiling project that has obvious imperfect tiles installed, like glaze missing on the edges, then it is simply because the tiler has not checked the tiles as he laid them. Defect tiles can slip through the factory. Faults like missing glaze on the edge of a tile, firing cracks, craters, bubbles, pinholes or smudged patterns. are all visible things and the installer should put these tiles aside and not use them.

So what do you do?

If the tiles have not been installed they should be returned and you should exchange them matching shades for the customer. The tiler should then install the new ones. Remember that no claims can be made once tiles have been laid.

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