Heavy 3 is a blue black slate with a slightly gritty texture, and in some samples well defined parallel lines are clearly visible on the cleavage surfaces.
Heavy 3 can last over a hundred years, making it a very cost-effective roofing material.
Its extra thickness of 7-8 mm gives it the perfect strength to withstand any weather conditions while boosting the value of any property.
Quarry Solana de Forcadas. San Pedro de Trones (León) Spain.
12x8”, 14x8”, 16x8”, 16x10” and 20x10”
CUPA Heavy 3 roofing slate meets the following international standards:
ASTM C-121 (S1), ASTM C-217 (S1), ASTM C-120 (S1)
BS 680 Part 2
NF 02/09 - Nº 17704
ATG H 571