A frequent query we receive at Stone Initiatives relates to “What are the properties of good building stones?”
While there is no one-size-fits-all answer to this question, there are a number of considerations and guides that specifiers, architects, designers and other built environment professionals can utilise when planning to use natural stone in a project.
Learning the basic properties of common building stones is a good place to start, and we share an introductory list later in this article. It is also important to understand the strengths and limitations of natural stone, what testing and analysis is recommended (this will depend on the stone type and your specific project), and any relevant Standards or building regulations that need to be adhered to.
The impact of stone’s uniqueness
While natural stone is often chosen as a building material for its uniqueness – no two pieces are exactly the same – it is precisely this uniqueness that can bring about variability in physical properties. This is one of the reasons that a thorough testing regime is recommended.
When stone is used for building construction without full knowledge of its properties, problems such as cracking, spalling, staining and decay can occur. By being aware of the potential as well as the limitations of the stone, its natural characteristics can be optimised during the design phase.
As part of the testing and analysis we can undertake at Stone Initiatives, factors such as the intended use of the stone (structural, pavers, façade etc), the type and location of the project, traffic / pedestrian load, environmental factors (is it in a particularly windy area, or will it be impacted by a salty environment, for example), and relevant Standards and building regulations are also considered. These factors, coupled with analysis of the stone product, can inform appropriate specification of the stone for the project.
An effective testing program is an essential tool in minimising the problems that can be involved with the use of natural stone.
Keys to stone selection
An earlier article written by Stone Initiatives principal Jim Mann, titled “Four Keys to Successful Stone Selection,” provides a comprehensive look at selecting and specifying the right stone for the job and can give some insight into the properties of good building stones. The article states that evaluation of basic technical data such as water absorption, strength (compressive and/or flexural), abrasion resistance and durability will “give you the ability to choose what best suits your needs.”
“Gaining information to make an informed choice can often be difficult, especially with the large volume of untraceable and untested material flooding into the country,” writes Jim Mann.
“As an end-user or specifier of stone, it is up to you to demand at least the basic information you require to make an informed choice.”
The article focuses on the four keys of stain resistance, strength, resistance to abrasion, and durability. They keys are relevant to all stone users and specifiers, and provide a useful starting point for choosing the right stone. The article also includes useful tables on tests that relate the these ‘four keys’ – the tables provide typical ranges and Standard requirements for common stone types. See the article here.
Properties of common stone types
As mentioned earlier, there is no one-size-fits-all answer to the properties of good building stones – but learning the basic properties of some common stone types is a good place to start. Below are some well-known properties of common stone types:
- Granite: A versatile stone available in colours ranging from light grey, to green or brown and even blue. It is known for its durability and strength, and has a very high abrasion resistance compared to most other types of dimension stone. Granite is also highly acid resistant, making it a great choice for kitchen bench tops, toilet floors and throughout entertaining areas. More here.
- Marble: An elegant stone that typically has a white background colour with varying bands, streaks or swirls. It can be cut or ground to a high polish, but has a relatively low abrasion resistance. The low hardness and characteristically fine grain size makes the stone suitable for carving into intricate statuary. More here.
- Alabaster-onyx: This fine-grain stone has wow-factor and is often used for statement pieces in design. However, as it is predominantly composed of calcium carbonate, it can be etched by acidic substances such as wine, soft drinks and some liquid soap. It has a low abrasion resistance but a relatively high flexural strength. More here.
- Travertine: A highly anisotropic material that has a distinctly different appearance depending on which way it is cut. Travertine is typically light cream to tan in colour. It is predominantly used as floor tiles, veneer cladding and paving. Will be etched by acidic substances such as wine, soft drinks and some liquid soaps. More here.
- Limestone: A versatile and highly variable stone type often used as thin tiles, large-format cladding, ashlar construction and statuary elements. Limestone is typically white to tan in colour, although there are darker colours on the market. Will be etched by acidic substances such as wine, soft drinks and some liquid soaps. More here.
Other useful resources
Beginner’s Guide to Material Selection: See the article here.
How to Choose the ‘Right’ Stone for the Job: See the article here.
Further information on Australian Stone Standards: See the Australian Stone Advisory Association website.
To discuss your project get in touch with our team.