What pitch can asphalt shingles be installed on with proper precautions?

Asphalt shingles can be installed on slopes as low as 2/12 when proper precautions are taken. At this pitch, it's essential to ensure that specific installation methods are employed to prevent water intrusion and to enhance the roof's waterproofing capabilities. This could include the use of starter strips and extra sealing around nails to create a tighter barrier against leaks.

Lower pitches like 1/12 would generally require specialized materials or techniques beyond standard asphalt shingle installation, making 2/12 the lowest pitch at which typical asphalt shingles can be safely used with precautions. The other pitches are above this threshold and therefore do not specifically highlight the need for the same level of caution due to their increased capability for drainage.