The UK roofing market is characterised by four main product types – natural slate, traditional clay, concrete tiles and increasingly, fibre cement slate. Go back seventy five years and there were just three options for roofing materials: quarry mined slates, which can suffer from inconsistent quality, size and thickness; clay tiles which are relatively expensive and factory-made concrete tiles which are inherently heavy. But over the past few decades, the popularity of fibre cement slates has grown as architects, contractors and homeowners have come to appreciate the aesthetic look, ease of installation and sustainable credentials of this material. A large proportion of new build developers now specify this material for residential projects and it is also increasingly prevalent in the domestic retrofit / replacement market.
Austrian industrialist, Ludwig Hatschek, invented fibre cement, a composite building material containing cement and fibres in the late 1800s. Initially, the material was used in panels as a facade on buildings, due to its low cost, low weight, excellent fire performance and water tightness. During the post-war era, its use grew significantly, with technical developments enabling the manufacture of roof slates, which were thinner and thus lighter than the panels. It may well be over a century old, but the development of the product continues apace.
Imported natural slates from countries such as Spain are becoming more popular as prices have fallen in recent years, allowing them to compete on price with fibre cement. However, there is much more to consider than just the per unit price at the merchants’ yard. Fibre cement slates perform well on key criteria including fire safety, protection against extreme weather, energy efficiency, sustainability, maintenance and lifespan.
Roofers also want a material that is easy to install. While Cedral’s fibre cement slates are all pre-holed, most natural slate alternatives are not. Grading is another important consideration when using quarry mined products, as these need to be quality checked and sorted by thickness before a project is commenced. Fibre cement slates are consistent in terms of quality and size, so are much more efficient from the outset. Fibre cement slates come in square or dressed edges, smooth or textured finishes and are available in a variety of colours such as Terracotta or Stone Green in addition to Blue-Black which mirrors the traditional slate grey colour. The manufacturers like Cedral also provide an expanding range of fittings and accessories, including ridges and hips, ventilation slates, verges and fixings.
Fibre cement slates are also a strong option for future proofing residential roofs against extreme weather. Fibre cement is resistant to all kinds of weather, from severe frosts and torrential rain to high heat and direct sunlight. With heavier rainfall becoming more normal in many places, the relative weight of the roofing can also be a key consideration for decisions about what material to specify.
The Met Office measured the highest amount of rain since its records began for any 18 month period in England from October 2022 to March 2024. The longer and heavier periods of rain have implications for the robustness of roofing tiles and fixings. Older roof structures, for instance, may not have the capacity to support heavier tiles if there are more prolonged periods of stormy and wet weather. Fibre cement slates are consistently lighter yet just as strong as clay, concrete and natural slate products. With the layered production and fibre matrix supporting the cement, fibre cement is thinner than concrete, but has the same performance benefits. They don’t require a heavy load bearing roof construction, so less timber is required for the structure.
Increasing temperatures can cause blistering or cracking on roof tiles and slates but fibre cement is highly resistant to intense temperature fluctuation with a minimum life expectancy of 50 years. It also withstands bacteria, algae and insects.
Sustainable building products are more important than ever for as architects and developers seek to ensure that their projects are responsibly designed, resourced and built. Manufacturers need to think about materials that are recyclable, to use less energy and to reduce waste. Fibre cement which is made of cement, water, cellulose, textile fibres and air can help improve circularity and carbonation impact. The innovations in fibre cement technology are creating high performing materials which are lighter, thinner and ultimately stronger. Cedral already supports refurbishment with robust, long-lasting material that is re-usable and with a production process that avoids causes of waste and uses local sourcing and transportation. In Europe, more than 70% of Cedral’s raw materials are sourced less than 200km from its factories.
The products are installed with reversible fixings, making them ideal in a circular context. The company has set ambitious targets which include zero waste and for the products to be fully recycled. The fibre cement roof slates have a carbon footprint of just 16 CO 2 e/m 2.
We anticipate that advances in sustainable construction will continue at a rapid pace, transforming home design. Fibre cement roofing tiles work well as an option for decisions about eco friendly building processes and materials.
By Lisa Grosse- Brand Manager for Cedral