Metal comes a close second to slate for longevity. Most metal roofs are expected to last 75 years (longer than some soft slates) and may last more than a century. Metal is also lightweight and much more affordable than stone tiles. Interlock Metal Roof Systems is serious about long-lasting roofs. Their motto is “Never reroof again,” and their minimum warranty is 50 years. Another option, although most of their products are asphalt shingle, is CertainTeed, a green-minded manufacturer of metal roofing. Some of their metal roof tiles come with lifetime warranties.