Asphalt shingles installed in warmer climates with a slope of 4 in 12 or more should have a minimum underlayment or:

Asphalt shingles installed in warmer climates with a slope of 4 in 12 or more should have a minimum underlayment or:

• A. 2 layers of #30
• B. 1 layer of #15
• C. 2 layers of #15
• D. 1 layer of #30

Answer: (B)

In asphalt shingle installations, underlayment choices depend on climate and roof slope. For a warm climate with a slope of 4:12 or greater, a single layer of 15-pound felt underlayment provides adequate secondary protection without added cost or weight. The heat and higher drying potential reduce ice dam and water intrusion risk, so extra layers or a heavier underlayment aren’t necessary. Heavier or multiple layers are reserved for colder climates, lower slopes, or conditions requiring extra protection, which is why they aren’t the correct choice here.

In asphalt shingle installations, underlayment choices depend on climate and roof slope. For a warm climate with a slope of 4:12 or greater, a single layer of 15-pound felt underlayment provides adequate secondary protection without added cost or weight. The heat and higher drying potential reduce ice dam and water intrusion risk, so extra layers or a heavier underlayment aren’t necessary. Heavier or multiple layers are reserved for colder climates, lower slopes, or conditions requiring extra protection, which is why they aren’t the correct choice here.