Grades Of Roofing Slate

N is cupa s natural selection.

Grades of roofing slate.

It is truly the result of a craftsmen s. This further highlights the traditional regional variations. Standard grade rough texture. S 1 will provide a service life of over 75 years s 2 will provide a service life of 40 75 years.

A standard grade slate cupa h selection will be less uniform and will require more sorting prior to use. Greenstone slate is measured by eye to thickness and is then split by hand. Grade s1 slate has an expected service life of more than 75 years. According to astm test c 406 roofing slate falls into three grades of classifications.

Grade s3 slate has an expected service life of only 20 to 40 years. Roofing slates are rated through the american standards of testing and materials and given a slate classification from s 1 to s 3. Welsh slate being very flat and smooth as well as a nominal 5mm thickness. Slate from cupa 5 and 18 quarries have more of a textured finish.

Welsh slate still comes in 3 grades referred to as capital 5 5mm thick county 7 mm thick and celtic 9 mm thick.