PRODUCT GUIDE Roof Accessories This standing-seam metal roof includes thin-film solar laminates. Kalzip uses a mechanical zipper systemalong with butyl-based sealants to provide the mechanically seamed, hydrostatic joinery required for a watertight metal flat roof. Metal roofs are fully recyclable and contain high recycled content. Photo: Kalzip Solar Solutions Behind the recommendations Related articles Behind the recommendations Related articles Roof Accessories Products with high recycled content, or that offer other unique performance features that contribute to durability More about Roof Accessories Better Choices in Low-Slope Roofing There are big differences in environmental impacts of commercial roofing materials, but the biggest variable may be service life. Stormwater Management: Environmentally Sound Approaches Stormwater management provides an excellent example of how, by making the most environmentally responsible choices, you can often save money as well.