Need some help in choosing the right stone tile for your next project? Learn stone’s basic properties and some simple selection methods.
Stain resistance
- Water absorption: High water absorption indicates that the stone will be more susceptible to staining from liquids, as these materials have greater capacity to hold the staining agents. The water absorption capacity of stone can vary greatly – granite can have water absorption of less than 0.1%, while some sandstone can have water absorption of more than 10%.
- Composition: Some stains are caused by a chemical interaction between the stone and the staining agent. For example, most marble types contain calcite and are therefore sensitive to acidic solutions.
- General appearance of the stone: Highly figured and variegated stone has more potential to hide a stain than a plain white stone with similar properties.
Abrasion resistance
Abrasion resistance is a property based on the hardness of the minerals that make up the stone and the strength of the bond of the grains within the stone. Low abrasion resistance will result in significant loss of polish, scratching and, in cases of high traffic, significant change in surface profile over time. In Australia, abrasion resistance is usually evaluated by determining its resistance to abrasion index -- the lower the index number, the lower the resistance to abrasion.
Therefore, choose a stone that has a high index number. In high traffic areas, consider using a stone that is less likely to show tracking paths, such as stones with honed, sandblasted, antiqued or sawn finishes.
Inherent strength
Strength is an inherent property that relates to the force the material can withstand per unit of cross-sectional area. The term “strength” may relate to either the compressive (crushing) or flexural (bending) strength of the material.
Flexural strength is highly relevant to the adequate performance of a dimension stone. Modern processing facilities now produce stone in longer and thinner slabs, which can be used to span greater distances with relatively lightweight units. Products such as large flagstones and veneer panels must have an adequate flexural strength to prevent the failure.
Durability issue
In Australia, the most common aggressive environments are related to rising damp and salt attack. A stone’s durability in these environments can be assessed by determining its resistance to salt attack. This test is specifically designed for sandstone, but is useful for testing other stone types such as low-density limestone.
Durability is also associated with water absorption. High water absorption can allow aggressive solutions, such as salt-laden or acidic water, into the stone where it can physically or chemically disrupt the structure of the stone. There are exceptions to this rule, as durability is also related to pore size. But if durability is important to you, choose a stone with a low weight loss after salt-attack testing, a low water-absorption capacity and high strength.
The right stone needs to meet requirements based on appearance and performance. As you carry out your project, seek help from one of these tiling experts in Australia.