Which roofing material has the longest expected lifespan?

Slate roofs are known for their exceptional durability and long lifespan, often lasting over 100 years with proper maintenance. This longevity is primarily due to slate's natural properties; it is a dense, metamorphic rock that is highly resistant to weathering, water absorption, and temperature fluctuations. As a result, slate roofs can withstand harsh environmental conditions, making them one of the most enduring roofing materials available.

In contrast, other roofing materials have shorter expected lifespans. Asbestos cement shingles have historically been used but have become less common due to health risks associated with asbestos. Roll roofing is generally favored for its low installation costs and ease of application, but it typically lasts only 5 to 10 years. Metal roofing offers durability and can last 40 to 70 years but does not surpass the longevity of slate roofs. Thus, the unique properties of slate contribute to its reputation as the longest-lasting roofing material.