Mineral surfaced roll roofing should not be applied on roof slopes with less than what percentage?

Mineral surfaced roll roofing is specifically designed for low-slope roofing applications, but it has certain limitations when it comes to the steepness or slope of the roof. The correct percentage that specifies the minimum slope for applying this type of roofing material is 3:12, or 25 percent. However, standards often suggest a minimum slope of around 2:12 or approximately 8.33 percent for practical applications. The choice indicating 8 percent aligns with the general consensus in the industry.

Applying mineral surfaced roll roofing on slopes less than this can lead to issues such as insufficient drainage, water pooling, and eventual leakage. It is crucial to maintain an adequate slope to allow water to flow off the roof efficiently and prevent long-term damage to the roofing system and the structure below. Thus, the designation of 8 percent serves as a guideline to ensure proper performance and longevity of the roofing system when mineral surfaced roll roofing is used.