Roof drains must extend their strainers not less than how many inches above the roof surface?

Roof drains are designed to effectively manage rainwater and prevent water accumulation on flat or low-slope roofs. The requirement for strainers to extend a specific number of inches above the roof surface serves several important purposes.

Firstly, the strainer must be elevated enough to allow for optimal drainage without obstruction from debris, leaves, or ice that might accumulate on the roof. This elevation helps ensure that water flows freely into the drain, reducing the risk of standing water that could lead to leaks or structural damage over time.

Secondly, a strainer height of at least 4 inches above the roof surface is suitable to accommodate variations in roof materials and conditions. This height helps prevent blockages and ensures that even if the roof is slightly uneven, the drain can still function effectively.

Maintaining this standard is critical for the durability of the roofing system as well as overall building integrity. Meeting this requirement contributes to proper drainage, which is essential in protecting a roof against water damage, thereby enhancing the longevity of both the roofing materials and the building structure itself.