True or False: Asphalt shingles should be used only on roof slopes of 2:12 or greater.

Asphalt shingles are typically designed to be installed on roof slopes of 2:12 or greater to ensure proper drainage and avoid water accumulation, which can lead to leaks and damage. A roof slope of 2:12 means that for every 2 units of vertical rise, there are 12 units of horizontal run. This slope allows rainwater to flow off the shingles effectively, preventing the risk of moisture intrusion.

When asphalt shingles are installed on roofs with a slope less than 2:12, they may not shed water adequately, increasing the likelihood of water pooling and potential roof failure. Thus, the guideline of using asphalt shingles on slopes of 2:12 or greater is based on ensuring the longevity and effectiveness of the roofing system in protecting against the elements.

The other options incorrectly imply that asphalt shingles can be used under different conditions unrelated to roof slope, which does not align with best practices for roofing installation.