Roof Drainage System Design

Functioning drainage system for steep slope roofs is to maintain a minimum roof slope.

Roof drainage system design.

A roof drain system s primary function is efficient water removal but in most cases it must also offer aesthetic appeal and on deck workspace. The design event used for sizing a roof drainage system will therefore not normally come out of a clear blue sky and then end equally suddenly but will have been preceded by a period of less intense rainfall. Establishing a minimum slope is critical because most steep slope roofing as. It is important for architects plumbing engineers and civil engineers to work together to design a system that will properly drain rainwater from a building and site.

For most dwellings you ll find that gutters range in size from approximately 100mm diameter to 150mm diameter assuming gutters with a half round section profile and downpipes range from approximately 60mm diameter to 90mm diameter assuming circular downpipes. There are various approaches that can accomplish this balancing act but each offers its own advantages disadvantages depending on a number of factors. Design considerations to keep in mind. Hence this is by far the most common roof drainage situation.

Typically a steep slope roof slope is equal to or greater than 3 inches of rise per 12 inches of run 25.