RTA members Roof tiles, whether made of concrete or clay, play a crucial role in protecting buildings from the elements while also contributing to their aesthetic appeal. In the United Kingdom, our weather conditions can vary dramatically, so ensuring the quality and durability of these roofing materials is fundamental. Therefore, rigorous testing and adherence to UK Standards is essential in the manufacturing and the installation of concrete and clay roof tiles.
Testing Procedures
Before any roofing material is deemed fit for use, it must undergo a series of comprehensive tests to assess its performance under a range of conditions. These tests evaluate factors such as strength, water resistance, durability, and resistance to environmental stresses. For both concrete and clay roof tiles, the testing procedures typically include:
Strength Testing – This involves subjecting the tiles to mechanical stress to determine their load-bearing capacity. For concrete tiles, this involves testing their flexural and compressive strength, while for clay tiles, it may involve assessing their resistance to breakage and impact.
Water Permeability Testing – Water absorption is a critical factor in determining a roof tile’s resistance to weathering and freeze-thaw cycles. Both concrete and clay tiles are subjected to water permeability tests to ensure their ability to repel water and prevent moisture ingress.
Fit Tests for Concrete Interlocking Tiles – Fit tests, including lateral shunt and engagement tests, are crucial components of ensuring the performance and longevity of concrete interlocking tiles. Lateral shunt tests evaluate the horizontal movement of interlocking tiles reducing the risk of roof damage or leaks. Engagement tests assess the depth of overlap between adjacent tiles when interlocked, to ensure a secure connection. Proper engagement maintains the integrity and effectiveness of the roof system according to established standards.
Freeze-Thaw Cycling: Given the UK’s climate, roof tiles must be able to withstand repeated freeze-thaw cycles without cracking or deteriorating. Tiles are subjected to cycles of freezing and thawing in controlled laboratory conditions to assess their resistance to this type of weathering.
Fire Resistance: Although essentially non-combustible, roof tiles must also meet certain fire safety standards to ensure the protection of buildings and occupants. Testing evaluates the tiles’ resistance to the surface spread of fire and their ability to prevent the spread of flames.
Both Clay and Concrete tiles manufactured to BS EN 1304 and BS EN 490 used on a conventional pitched roof with insulation, underlay, battens and tiles are deemed-to-satisfy the UK building regulations with respect to external fire performance and are designated Class AA in BS 476 – 3. The European external fire performance classification applicable to roof coverings made of clay or concrete determines that they are incombustible and have a reaction to fire rating of BROOF (t4) in BS EN 1187.
Adherence to Standards
In the UK, RTA roof tile members adhere to all the British and European standards to ensure the quality and performance of their products. These standards outline the requirements for materials, manufacturing processes, testing procedures, and performance criteria for roof tiles. Some of the key standards applicable to concrete and clay roof tiles include:
BS EN 490 & BS EN 491: Concrete roofing tiles and fittings – These standards specify the requirements for concrete roofing tiles and fittings and test methods, including dimensional tolerances, mechanical properties, and methods of test.
BS EN 1304: Clay roofing tiles and fittings – The standard covers clay roofing tiles and fittings, providing specifications for materials, dimensions, and performance characteristics.
BS 5534: Code of practice for slating and tiling – This British Standard provides guidance on the design and installation of roofs using slates and tiles, including concrete and clay tiles. It covers aspects such as fixing methods, underlays, and eaves details to ensure the longevity and weather-tightness of the roof.
NHBC Standards – The National House-Building Council (NHBC) sets standards for new home construction in the UK, including requirements for the installation of roof tiles. Compliance with NHBC standards is often a prerequisite for obtaining warranties and insurance for new properties.
Conclusion
RTA members testing and adherence to standards are integral aspects of ensuring the quality, durability, and safety of concrete and clay roof tiles in the UK. By subjecting these materials to rigorous testing procedures and complying with established standards, manufacturers can produce reliable roofing products capable of withstanding the challenges posed by the UK’s climate. Likewise, adherence to standards in the installation of these tiles helps to ensure that roofs perform effectively and provide long-lasting protection for buildings and their occupants and will provide assurance as to the fitness for purpose. As the construction industry continues to evolve, maintaining high standards in roofing materials and good practices remains essential element for the resilience and sustainability of all types of buildings across the UK.