Information and video guides from Independent Slate Supplies U.K. Independent Slates Supplies (ISS) are specialists in the import and distribution of high quality, competitively priced roofing and flooring products including: Natural Slate Roofing, Natural Slate Flooring Natural Slate Sills and Hearths Fibre Cement Slates, Ventilation, Hips and Ridges Accessories including nails, hooks, adhesive, grout and sealant