To achieve effective drainage, what must be ensured about a rainwater leader?

To achieve effective drainage, having the rainwater leader properly sloped is crucial. Proper sloping ensures that rainwater flows smoothly and efficiently from the roof or upper areas down toward the drainage system without pooling or backing up. A slope directs the gravitational flow, minimizing the risk of stagnation, which can lead to water damage, mold growth, and other issues associated with poor drainage.

While insulation might be considered in certain climates to prevent freezing, it is not a primary requirement for effective rainwater drainage. Connection to a downspout is also important, but it is not the defining factor for achieving efficient drainage—it is more about directing the water correctly. Material choice, such as being made of PVC, may have advantages in terms of durability and weight, but it does not directly influence the functional effectiveness of drainage if the slope is not appropriately managed. Therefore, proper sloping stands out as the most critical aspect for ensuring that rainwater leaders function effectively in draining water away efficiently.