How using clay roof tiles can support sustainable housebuilding

When it comes to sustainable roofing materials, the traditional choice still remains one of the best. Clay roofing tiles are known for their timeless charm and natural beauty – but they’re also one of the most environmentally friendly roof coverings available.

With increasing pressure on the construction industry to reduce the environmental impact of the built environment, architects, specifiers, developers and housebuilders are all looking for ways to improve sustainability, without compromising on performance or significantly increasing costs.

Clay roof tiles have been used for centuries, and they continue to be a popular choice due to their aesthetics. However, their environmental credentials are not as widely known, which is a shame because they have a lot to boast about. Our clay roof tiles EPD (environmental product declaration) provides a comprehensive overview of the environmental impact of this roof covering. In this blog post, we’ll take a look at some of the ways that clay tiles can support sustainable housebuilding.

The low-carbon lifecycle of clay roofing tiles

Something that really stands out about clay roofing tiles is their low embodied carbon. That is the total carbon emissions that can be attributed to the product during their entire lifespan. From the extraction of the raw materials, through to their production, use and end of life, clay roof tiles have a minimal environmental impact at almost every stage.

• Natural and abundant raw materials – The only raw materials required for clay roofing tiles are clay and water. Pigments and/ or sand may also be added to the mix to change the colour and texture of the tiles. Marley clay plain tiles are made from Etruria Marl clay, which produces high-quality and durable roofing tiles with minimal processing. And since it comes from sources in central England and Wales, transport is kept to a minimum.
• Minimal manufacturing waste – Since clay tiles are made using natural materials, very little waste is generated during the manufacturing process. Any water lost during the manufacture of Marley’s clay roofing tiles is recycled – it’s collected and reintroduced to the mix. Material waste is also negligible and is typically recycled.
• Longevity and minimal maintenance – Once clay roof tiles are manufactured, they are incredibly strong and long-lasting. While manufacturers typically list the lifespan of clay tiles as 50 to 60 years, many roof tiles currently in use today are over 100 years old, and archaeologists have found evidence of clay roof tiles dating back 10,000 years. While we can’t promise lifespans of millennia, we can say that Marley’s clay roof tiles should last for decades, and their minimal upkeep requirements and durability will help to minimise the carbon costs of maintenance, repairs and replacement.
• End-of-life reuse or recycling – When clay roofing tiles reach the end of their lifespan, they can be crushed and used as a base material for new tiles or other building materials. This reduces the need to use virgin aggregate and supports a circular economy. Based on the UK government’s statistics on construction waste, we can assume that more than 90% of clay roofing tiles are recovered and reused during non-hazardous construction and demolition.

In fact, the only part of a clay roof tile’s lifespan that isn’t low carbon is the firing stage. Firing is an essential part of the manufacturing process as it hardens the clay to make it strong and resilient. Heating kilns to the necessary temperature can be energy intensive, but Marley is working to reduce the environmental impact of firing, using more efficient kilns and exploring alternative technologies and fuels.

Why EPDs matter for clay roof tiles and sustainable housing

With carbon targets and environmental certification schemes like BREEAM and LEED becoming increasingly important, specifiers must be aware of how building product selection impacts the overall sustainability of a project. Environmental Product Declarations, also known as EPDs, can provide valuable data to help specifiers make informed decisions and ensure sustainability targets are achieved.

Marley’s clay roof tile EPD covers our entire range of clay roofing tiles, demonstrating their whole-life carbon footprint and how they can support sustainable housebuilding.

The Marley clay roofing tiles EPD can be downloaded from our dedicated EPD page. For technical support with your next project or to discuss our clay tiles in more detail, please contact the Marley team.