What is the minimum slope required for coal tar built-up roofs?

The minimum slope required for coal tar built-up roofs is 1/8:12. This slope is significant because it ensures proper drainage of water off the roof surface, which is crucial in preventing water pooling and subsequent damage or deterioration to the roofing material. A slope of 1/8:12 allows for sufficient runoff to avoid leaks, extend the life of the roofing system, and maintain compliance with building codes and best practices in roofing design.

In roofing applications, insufficient slope can lead to water accumulation, which can cause structural issues over time, while also increasing the likelihood of mold and mildew due to prolonged moisture exposure. Therefore, the 1/8:12 slope is a standard that helps ensure that the roofing system is effective and durable, making it the correct choice in this scenario.