What is an acceptable roof slope for asphalt roofing sheeting?

• A. 1 unit in 12
• B. 2 units in 12
• C. 3 units in 12
• D. 4 units in 12

Answer: (B)

The main idea here is the minimum pitch that asphalt shingles are designed to perform on. For standard asphalt roofing, a slope of 2:12 is the minimum accepted pitch. At this incline, water can shed effectively and the shingles can be nailed and sealed properly, reducing the risk of leaks and wind uplift. Slopes lower than this, like 1:12, are too flat for conventional asphalt shingles and typically require a different roofing material or additional underlayment designed for low-slope applications. Slopes of 3:12 or 4:12 are also acceptable, but the question focuses on the minimum acceptable slope, which is 2:12.