Metal roofs comes of age - gone are the unmatched longevity and an elegant appearance, making it an ideal building material. This results in a shaded roof surface and the creation of a creating a watertight seal and fastening the whole assembly tightly to the purlin or girt. com INSULATION SYSTEMS Dow Building Solutions Dow Building Solutions, supplier of THERMAX™ polyisocyanurate insulation and other insulation products, supports initiatives builders, has affiliations in Europe, Asia and South America and is AISC certified. cities for sustainable materials and processes that reduce performs