What is the minimum acceptable slope for steep asphalt roofing?

The minimum acceptable slope for steep asphalt roofing is typically 1/4" per 12" of horizontal run. This slope allows for adequate water drainage and helps prevent water pooling on the roof, which can lead to leaks and structural damage over time.

Choosing a slope of 1/2" per 12" of run would actually represent a steeper slope than the minimum required, thus allowing for even better drainage and helping to prevent moisture issues more effectively. This can also reduce the load on roofing materials by ensuring water runs off more rapidly, which is particularly beneficial in areas prone to heavy rainfall.

It is worth noting that while other options indicate steeper slopes, they exceed the minimum requirement. The 1/4" per 12" slope is a widely accepted standard for steep roofing, but building codes may vary, and certain applications may warrant even steeper slopes for optimal performance.