Slate is among the most durable of all roofing materials. Not all slate is the same—some comes from quarries in Vermont, some from Pennsylvania and other states—but the best of it will outlast the fasteners that hold it in place. Hundred-year-old slate, in fact, is often recycled for reinstallation, with the expectation it will last another century. But slate is expensive—typically prices start at about $800 a square—and very heavy.