For roofing tile, what is the minimum underlayment requirement?

For roofing tile, what is the minimum underlayment requirement?

• A. Two Type 15 or One Type 30
• B. One Type 15
• C. Two Type 30
• D. Three Type 15

Answer: (A)

When installing roofing tile, an underlayment acts as a secondary moisture barrier and protects the deck from leaks around fasteners and through small imperfections. For tile roofs, the minimum requirement is two layers of 15-lb felt, or a single layer of 30-lb felt. This setup provides enough protection even if water penetrates the tile level and ensures the roof remains watertight during weather and installation issues. Using only a single layer of 15-lb felt or anything lighter wouldn’t meet the standard protection tile roofs require, while choosing two layers of 15-lb or a single 30-lb layer gives equivalent, sufficient coverage.

When installing roofing tile, an underlayment acts as a secondary moisture barrier and protects the deck from leaks around fasteners and through small imperfections. For tile roofs, the minimum requirement is two layers of 15-lb felt, or a single layer of 30-lb felt. This setup provides enough protection even if water penetrates the tile level and ensures the roof remains watertight during weather and installation issues. Using only a single layer of 15-lb felt or anything lighter wouldn’t meet the standard protection tile roofs require, while choosing two layers of 15-lb or a single 30-lb layer gives equivalent, sufficient coverage.