74 RCI 0614

RCI June 2014

PITCHED ROOFING Concrete vs Clay Mark Parsons of Russell Roof Tiles (RRT) explains why he feels concrete roof tiles There is often an argument when looking at sustainability that a material seen as “naturally” occurring is more sustainable than that of a manufactured product. But the distinction is not always so clear cut. One area where this is specifically an issue is the concrete versus clay roof tiles debate. Though both are “manufactured” from natural materials such as sand, water, clay and limestone, concrete is still seen as unnatural and a synthetic roofing material, whereas clay tiles are often marketed as a “natural roofing product.” As product development has evolved, the evidence suggests that concrete roof tiles are a far more sustainable option. Despite concrete roof tiles first being developed in the 19th century they are still seen as a relative newcomer. In fact the earliest large-scale users of concrete were the ancient Romans, and concrete was widely used in the Roman Empire. Rome’s Coliseum was built largely of concrete, and the dome on the Pantheon is the world’s largest unreinforced concrete dome. After the fall of the Roman Empire, widespread use of concrete became rare until the technology was re-pioneered in the mid-18th century. Today, concrete is in fact the most widely used man-made material. Concrete roof tiles first gained a real foothold in the market following the post war housing boom, where manufacturers tooled up and invested heavily in automation. Concrete tiles now account for around 60% of the market and are used widely as a standard material across the UK. Clay tiles are often seen as a more environmentally-friendly product, as opposed to concrete, but when looking at the whole manufacturing process and comparing the entire 074 JUNE 2014 RCIMAG.COM should be considered as a serious, sustainable option process, concrete is in reality more sustainable. Sustainability, as we all know, continues to be a major issue in construction, particularly in housebuilding. Compared to traditional clay roof tiles, concrete tile manufacturing requires considerably less energy usage during production. This is largely because of the extensive power required for clay tiles, in a 1000ºC+ kiln for up to 48 hours. Concrete tiles are cured at a much lower temperature and for only a short amount of time. This means that an energy saving of up to 30% of that energy used in the production of clay tiles can be achieved when comparing the production of raw materials and production. Concrete tiles have a much lower embodied carbon than those of clay as well. This means that clay tiles require a greater energy input throughout their production process before the final product is compete. Although cement does have a high carbon embodiment, it typically represents less than 20% of the weight of the tile composition. The remainder of the materials used in production are “natural” products. A study in 2008 showed that during its entire lifecycle, a concrete roof tile only creates around 45% of the greenhouse gases triggered by a clay roof tile during its lifetime. Concrete roof tiles are a long life, durable product and require minimal maintenance once installed. The versatility of concrete allows for an authentic slate or clay effect roof tile, with the benefits of offering greater strength. Concrete tiles allow for a straight forward quick installation and then after will require little or no maintenance as they are highly resistant to freeze thaw conditions. Modern techniques now enable manufacturers like us to replicate the traditional character of regional clay colours and profiles, but with all the long-term added benefits of concrete. We have recently launched the Regency Range which offers plain tile combinations with the benefits and durability of concrete and a traditional clay look appearance. This effect is created by using different percentages of each colour tile to achieve the overall desired effect. This new range currently has six standard blends, however bespoke blends can be created for individual projects to suit specific local planning requirements. Embodied carbon is something that is likely to have a greater importance for housebuilders in the future. The government’s ‘Code for Sustainable Homes’ is becoming more centred around reducing not only the carbon footprint of finished buildings, but also the carbon footprint of materials that go into their construction. So, in my view, it’s time that concrete was considered as a serious sustainable option over its “natural” clay cousin. www.russellrooftiles.com The Windsor blend Mark Parsons, commercial technical manager at RRT “The government’s ‘Code for Sustainable Homes’ is becoming more centred around reducing not only the carbon footprint of finished buildings, but also the carbon footprint of materials that go into their construction”


RCI June 2014
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