Roofing Slate Specifications - Slate Standards & Roof Slate Weights
Roofing slate specifications are published in the table below. The data is supplied by the manufacturers and is based on their most recent tests which are usually carried out each year to ensure that the slate meets the required standards.
Bellstone supplies only those slates that meet either the ASTM (American) or BS EN (British Standards / European Norme) standards.
| Quarry | Penrhyn | Penrhyn | Penrhyn | Glendyne | Cupa R6 |
| Country of Origin | Wales | Wales | Wales | Canada | Spain |
| Slate Type | Capital | Capital | County | 4's | R6 |
| Quality | Premium | Premium | Premium | Premium | Primera |
| Size (mm) | 500x250 | 500x300 | 500x300 | 508x254 | 500x250 |
| Pre-holing (distance from top)
|
200mm
|
-
|
-
|
190mm
|
-
|
| Thickness | 5.5mm | 5mm | 8mm | 5.5mm | 4 – 5 mm |
| Wt / Slate (kgs) | 1.86 | 2.23 | 2.83 | 1.78 | 1.45 |
| Slates / * covered m2 | 19.1 | 16.0 | 16.0 | 18.9 | 19.1 |
| Wt (kg) / * covered m2 | 35.5 | 35.7 | 45.3 | 33.6 | 27.7 |
| Colour | Heather Blue | Heather Blue | Heather Blue | Charcoal Grey | Black |
| BS EN
|
Yes
|
Yes
|
Yes
|
-
|
Yes
|
| ASTM C406-06 | S1 | S1 | S1 | S1 | S1 |
| Service Life (ASTM C406) | 75+ years | 75+ years | 75+ years | 75+ years | 75+ years |
| Guarantee | 100 years | 100 years | 100 years | - | - |
* Calculations based on 90mm headlap & 5mm joint gap; more slate is required for bigger headlaps.
Allow for up to an extra 0.5 slates/m2 for eaves, cuts and wasteage.
Please note that slate is not recommended for roof pitches less than 20 degrees.
Go to Roofing Slate User Guide for handy hints on specifying slate.