What must be ensured for proper water diversion on roof systems?

For proper water diversion on roof systems, it is crucial that water is directed outside the wall covering. This ensures that water does not accumulate or penetrate behind the walls, which can lead to significant structural damage, mold growth, and compromised insulation. Properly directing water away from the wall coverings allows for effective drainage and minimizes the risk of leaks or moisture-related issues that could jeopardize the integrity of both the roof and the building itself.

While keeping insulation dry and having an appropriate roof pitch are important for overall roof performance, the primary goal of water diversion is to manage drainage properly, hence making sure that water is routed away from the walls is the fundamental aspect of effective roof design. Lightweight materials may have benefits in terms of structural load, but they are not necessarily a requirement for effective water diversion.