Why do roofs with flatter pitches have shorter lifespans?

Roofs with flatter pitches tend to have shorter lifespans primarily because they shed moisture more slowly. When a roof has a flatter pitch, water and snow can accumulate on its surface for a longer period of time after precipitation. This can lead to prolonged exposure to moisture, which can deteriorate roofing materials over time.

As moisture remains on the roof, it increases the potential for issues such as mold growth, algae buildup, and even structural damage if water seeps beneath the roofing materials. In comparison, roofs with steeper pitches allow water to drain off more effectively and quickly, reducing the risk of moisture-related problems. This fundamental characteristic of flat roofs directly impacts their longevity, making moisture management a critical aspect of their design and maintenance.