Metal roofs can stand up to nearly anything Mother Nature throws at them, so you’ll find that they come with 30- to 50-year warranties, and often outlast that with lifespans of 40 to 70 years. Metal roofs are not without weaknesses, however: Extreme hail or falling branches could dent a metal roof, as could walking on it improperly. Shingles have a shorter lifespan due to their own unique set of weaknesses. Pooling water and chronically damp conditions can lead to algae and fungus growth, ice dams can create cracks, and temperature spikes between day and night can reduce the life of your shingle roof.