Slate – Not such a simple choice

Editorial by MD John Sayers

As indigenous slate becomes more expensive and rarer to source, the UK industry has had to look to wider European and world markets to fulfil demand, resulting in slate from Spain, Brazil, Canada, America and China flooding into the market.

As a natural product, the quality and characteristics of slate can vary dramatically from region to region and country to country. When used for roofing it really is a case of only the best will do, with quality varying at different quarries and some of the products on the market unsuited for roofing applications due to their geological formation.

Slate rock sourced in certain locations can be said to have what geologists class as ‘slaty cleavage’, a term used to indicate that the rock can be split into very thin layers, whilst retaining a tremendous strength, making it particularly suitable for use as roofing slate.

The industry has developed the BS EN 12326 Certification to test certain key properties of the slate. Key checks include:

  • Thermal Cycle (Look out for T1, the highest quality rating for slate)
  • Sulphur Dioxide Exposure (Look out for S1, the highest quality rating for slate)
  • Water Absorption (Look out for A1, the highest quality rating for slate)

Whilst this certification has been adopted as standard across the industry it is not the end of the story. An experienced and talented slater will always be able to identify the difference in the quality of slates, even amongst those that have all passed the certification requirements. It is therefore essential that you bring in a tradesperson with experience when identifying the correct slate required for roofing projects.

At Hodgson Sayers we have over 30 years of experience in the roofing industry, we always ensure we use premium grade natural products which we visually inspect and test before we commit to use.

Our slaters also prefer to use best quality products, increasing efficiency in the grading and sorting process, reducing overall installation times, and leaving our customers with a high-quality finish that is durable and attractive.

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