Grades Of Roofing Slate

Greenstone slate is measured by eye to thickness and is then split by hand.

Grades of roofing slate.

Standard grade rough texture. N is cupa s natural selection. Grade s1 slate has an expected service life of more than 75 years. A standard grade slate cupa h selection will be less uniform and will require more sorting prior to use.

It is truly the result of a craftsmen s. This further highlights the traditional regional variations. Slate from cupa 5 and 18 quarries have more of a textured finish. But the finished project will look as good if due care is taken of the slate grading.

Welsh slate still comes in 3 grades referred to as capital 5 5mm thick county 7 mm thick and celtic 9 mm thick. S 1 will provide a service life of over 75 years s 2 will provide a service life of 40 75 years. Welsh slate being very flat and smooth as well as a nominal 5mm thickness. Grade s3 slate has an expected service life of only 20 to 40 years.

Grade s2 slate s service life is 40 to 75 years.