What is the minimum slope for installing asphalt strip shingles per code?

• A. 1:12
• B. 2:12
• C. 3:12
• D. 4:12

Answer: (B)

The minimum slope for installing asphalt strip shingles, as per standard code, is 2:12. This means that for every 12 horizontal units, the roof must rise at least 2 vertical units. A slope of 2:12 is considered the minimum because it allows for adequate drainage of water, preventing issues such as leaks or water pooling, which can lead to roof damage over time.

Installing shingles on a slope lower than 2:12 can compromise their effectiveness. Water may not run off properly, and the shingles may not adhere as intended, increasing the risk of failure. Higher slopes, like 3:12 or 4:12, are generally acceptable and may even be preferable for performance and longevity, but the code specifies 2:12 as the baseline requirement to help ensure the roofing system functions properly.