We don’t often think of tile or stone products as being particularly harmful, as far as materials go.
Unlike other wall and floor coverings, they don’t prompt questions about sustainable forestry practices, or volatile organic compound (VOC) emissions, or poor indoor air quality. After all, stone is a natural material, so what’s the issue?
Naturally occurring substances, such as clay, sand and rocks, have been quarried and used for construction work for as long as history can recall. Nowadays, manufacture of hard surfacing products is an established industry and a major part of the multi-billion dollar building industry. The biggest direct impact of these industries is on the environment: the energy spent in sourcing the raw materials, the adverse effects of quarries, and the air and water pollutants emitted during the finishing operations.
Considering the size of the tile and stone industry and the amount of sourced, finished and installed hard surfacing products, it’s important to know exactly what the environmental impacts are, and how to best minimise them.
Quarrying, fabrication and testing of stone products is more sophisticated than ever before, with constant technical improvements paving the way to establish best practice methods to lower the environmental footprint of the stone industry sector.
Efficiency across all aspects of operations is key for water use, for energy use, for extracting usable materials and minimising waste, and even for the fuel used by operating equipment at the site. Minimising waste and resources used is always the first step toward a reduced overall environmental impact. Even product packaging is important to consider from a waste management perspective: the amount used, its capacity to be recycled, and whether or not it contains hazardous materials.
Water use and efficiency is one important part of the process for obtaining raw materials. Mining and quarrying should not interfere with confined aquifers, and surface water should not be used if the water body is located within drinking water catchment areas, national parks, or other areas identified as having ecological significance.
It’s also important to minimise water use wherever possible through practices such as water recycling and rainwater collection. Finally, any treated waste water discharged from the site must have only a minimum of suspended solids and heavy metals present.
Like emissions to water, emissions to air must also be strictly limited. The production and finishing of tile and stone products can result in emissions of dust, sulphur dioxide, nitrogen oxides, fluorine and/or styrene, all of which must be carefully controlled. The finishing process in particular can have an impact on the health of workers, so a human health risk assessment should ideally be carried out to minimise risk of harm from air emissions.
There's also the combined health and environmental impact of many modern tile and stone products, such as engineered stone, to consider. These can contain several additives, binders, flame retardants and resins to improve performance and affordability, which can present their own hazards.
Quarrying and mining, by their very nature, are environmentally destructive practices. That’s why it’s important that those responsible for the site are also responsible for rehabilitating the land and having an environmental remediation plan in place.
The biggest downside to tile and stone products compared to other flooring materials is that they have a high embodied energy (the sum of all the energy required to produce something). Even bigger impacts occur when you consider imported stone tiles; the energy and processes required to ship them internationally adds significantly to their environmental load.
Many of these impacts may not be obvious to the end user. There’s less of a market demand for perceived “eco-friendly” or “green” tiles compared to other surface finishes like carpet or hardwood. However, the demand for tile and stone products in general is strong in Australia thanks in part to our hot climate and desire for a nice cool floor.
"Greener" tile and stone products can fit into the Green Building Council of Australia's Green Star system thanks to the "sustainable products" credit in the new rating tools. The credit works on the basis of the percentage of sustainable products used in a project by dollar cost and includes floor finishes such as tiles. Since tiles cover a larger surface area, these can form a significant percentage of the total cost of a fitout, which translates into greater potential for earning those valuable credit points in Green Star projects.
It would be great to see more tile and stone manufacturers take action to lower the environmental impact of their operations and push “greener” hard surfacing products into the mainstream market.