Cambrian Slates embody the beauty and character of natural slate. Made in Wales from over 60% recycled Welsh slate, Cambrian tops the range in both looks and performance and has a proven track record even on pitches as low as 15. Whilst light in weight, Cambrian's unique three point fixing makes it suitable for even the most exposed sites. Properties Size: 300mm x 336mm. Minimum pitch: 15 at 75mm headlap. 25 at 50mm headlap. Maximum pitch: 90. Coverage: 15.9 slates/m2 - 210mm guage. 14.8 slates/m2 - 225mm guage. 13.3 slates/m2 - 250mm guage Weight: 1.24 tonnes/1000. Batten size: 38mm x 25mm - rafter centres up to 400mm. 50mm x 25mm - rafter centres up to 600mm. Battens required: 4.76m/m2 - 210mm guage. 4.44m/m2 - 225mm guage. 4.00m/m2 - 250mm guage. Nail size: 30mm x 2.65mm. Certification BBA certified.