On what type of roof slope are asphalt shingles NOT permitted to be installed?

Asphalt shingles are not typically permitted to be installed on a roof slope of 2 in 12. Roof pitch is an important consideration for the performance and longevity of roofing materials. For asphalt shingles, a minimum slope of 3 in 12 is generally recommended to ensure proper drainage, minimize the risk of water infiltration, and promote the effective shed of rainwater and snow. At a slope of 2 in 12, water can accumulate and may not flow off the roof appropriately, increasing the likelihood of leaks and potential damage. Thus, installations on roofs with a pitch less than this threshold may void warranties and can lead to significant maintenance issues. Each roofing material has specific guidelines to follow to optimize its effectiveness and durability, which is essential for proper building performance.