01
From rock to roofing unit
Slate begins as fine-grained rock that developed a natural cleavage under heat and pressure. Skilled production follows that cleavage to split comparatively thin roofing units. The way a deposit cleaves, the presence of inclusions and the consistency of production all affect the finished material.
02
Roofing slate is a performance product
A sample can show color and surface character, but it cannot by itself establish the performance of a shipment. Source identity, product grade, thickness, dimensional tolerances, test documentation and representative production samples belong in the selection process.
03
Variation is part of the material
Natural slate can show texture, shade and thickness variation. Good specifications define what variation is expected and how material will be sorted and blended. The goal is not to make stone behave like a factory-colored sheet; it is to control natural variation while preserving reliable roof geometry.