What is the minimum recommended slope for roof drainage in general construction?

The minimum recommended slope for roof drainage in general construction is often cited as 2:12. This means that for every 12 horizontal inches of roof, the slope should rise at least 2 inches vertically. This slope is necessary to ensure that water drains properly off the roof surface and does not pool, which can lead to water damage, leaks, and increased wear on roofing materials.

A slope of 2:12 helps to facilitate adequate drainage while still being manageable for roofing materials and construction methods. This slope minimizes the risk of standing water, which can compromise the integrity of roofing systems over time due to potential leaks and decay.

In contrast, slopes that are less steep may not allow proper water runoff, leading to various issues, while steeper slopes may exceed the practical capabilities of certain roofing materials or make installation more difficult.

Therefore, maintaining at least a 2:12 slope is essential for effective roof drainage and the longevity of the roofing system.