Water Absorption and Tiles: Myths Vs Facts!

What is water absorption for tiles?

Tiles are categorized based on their water absorption capacity, which is the amount of water they can retain, typically presented as a percentage of their dry weight. According to MS ISO 13006, which outlines the guidelines for manufactured tiles, the various types of tiles are grouped based on their specific water absorption rates:

Tiles with low water absorption, under 0.5%, fall into the category of porcelain tiles. Ceramic floor tiles typically have a water absorption rate ranging from 3 to 10%, while ceramic wall tiles have a water absorption rate exceeding 10%, making them ideal for wall applications.

What causes water absorption in tiles?

Ceramic and porcelain tiles are manufactured by firing a blend of raw materials at high temperatures to create a solid, durable tile. Although both types are clay-based, porcelain tiles have additional fluxing agents like feldspar and talc in their composition. They undergo higher pressure during pressing and are fired at elevated temperatures, resulting in a denser structure compared to ceramic tiles. This density contributes to the superior hardness, strength, and chemical resistance of porcelain tiles, making them ideal for heavy-duty use in commercial, outdoor, and high-traffic areas.

The denser nature of porcelain tiles means they have fewer pores or tiny gaps within their structure, reducing water absorption. This characteristic makes water absorption a reliable indicator of a tile’s density.

How is water absorption tested?

After tiles are produced, a sample undergoes various tests to check its performance and adherence to standards. One critical test is the water absorption test, involving boiling a dry tile in water for 2 hours and soaking it for an additional 4 hours to assess its water absorption rate.

Several myths surround water absorption and tiles, including: