Standard Roofing Slate Thicknesses and Sizes

A. Thicknesses

1. Standards; Nominal 3/16 inch (5 mm) to 1/4 inch (7 mm)

2. Quarters; Nominal 1/4 inch (7 mm) to 3/8 inch (10 mm)

3. Heavies; Nominal 3/8 inch (10 mm) to 1/2 inch (13 mm)

4. Extra Heavies; Nominal 1/2 inch (13 mm) to 3/4 inch (19 mm)

 

B. Standard Slate Sizes

1. 24”L X 14”W (610 mm X 356mm)
2. 24”L X 12”W (610 mm X 305 mm)
3. 22”L X 12”W (559 mm X 305 mm)
4. 22”L X 11”W (559 mm X 279 mm)
5. 20”L X 14”W (508 mm X 356 mm)
6. 20”L X 12”W (508 mm X 305 mm)
7. 20”L X 11”W (508 mm X 279 mm)
8. 20”L X 10”W (508 mm X 254 mm)
9. 18”L X 14”W (457 mm X 356 mm)
10. 18”L X 12”W (457 mm X 305 mm)
11. 18”L X 11”W (457 mm X 279 mm)
12. 18”L X 10”W (457 mm X 254 mm)
13. 18”L X 9”W (457 mm X 229 mm)
14. 16”L X 14”W (406 mm X 356 mm)
15. 16”L X 12”W (406 mm X 305 mm)
16. 16”L X 11”W (406 mm X 279 mm)
17. 16”L X 10”W (406 mm X 254 mm)
18. 16”L X 9”W (406 mm X 229 mm)
19. 16”L X 8”W (406 mm X 203 mm)
20. 14”L X 10” W (356 mm X 254 mm)
21. 14”L X 9”W (356 mm X 229 mm)
22. 14”L X 8”W (356 mm X 203 mm)
23. 14”L X 7”W (356 mm X 178 mm)
24. 12”L X 10”W (305 mm X 254 mm)
25. 12”L X 9”W (305 mm X 229 mm)
26. 12”L X 8”W (305 mm X 203 mm)
27. 12”L X 7”W (305 mm X 178 mm)
28. 12”L X 6”W (305 mm X 152 mm)