Slate: Slate roofing tile has a long and storied history, and is generally known as one of the highest quality, longest lasting roofing materials on the market. On the other hand, the high cost, difficult installation, and relative fragility of slate roofing tile means it’s not ideal for everybody. Slate roofs can and should be routinely built to last at least a century. In fact, 150 years is a reasonable expectation of a roof’s longevity if the roof is properly constructed. That’s a big plus in an industry where many roofing systems are lucky to last 20 or 30 years before needing replacement. Roofing waste accounts for more than 5 percent of the total waste sent to landfills across the nation every year. Since the majority of that roofing waste can be attributed to asphalt shingle roofing that needs replacement every 20 to 30 years, it’s easy to see the positive environmental impacts of installing a roof that is going to last 100 years or more.