01
Know the exact source
Performance can vary by deposit, quarry, production selection and grade. Proposals should identify the producer, product, dimensions, thickness and finish rather than relying only on a country label. Traceability is especially important when matching later additions or repairs.
02
Review relevant testing
Ask for current product-specific documentation addressing absorption, strength, weathering and the standards applicable to the project. Imported material may be accompanied by European and North American test information; the design professional should decide what the specification requires.
03
Confirm sorting and installation expectations
Thickness calibration, surface texture and edge character affect handling and finished appearance. Samples should be representative, not hand-selected showpieces. Storage, blending, cutting and fastening practices should reflect the actual slate delivered.