What is the maximum slope for double underlayment application of clay and concrete roof tile?

The correct answer is based on industry standards for the installation of clay and concrete roof tiles, which are typically designed to ensure proper drainage and minimize the risk of water intrusion. A maximum slope of 4 units vertical in 12 horizontal (which is equivalent to a 1:3 slope) is the standard for double underlayment applications. This slope allows for adequate water run-off, thus enhancing the roof's effectiveness in directing water away from the building structure.

When the slope exceeds this standard, the risks associated with water accumulation and potential leaks increase, which can compromise the integrity of the roofing system. A steeper slope might be appropriate for other types of roofing materials, but the maximum slope for double underlayment with clay and concrete tiles remains at this specified limit to ensure optimal performance and durability of the installation.