Recommended size of horizontal storm drains below or above ground can be found in the table below. The drained area may be roofs, paved courtyards or similar.
|Drain pipe diameter||Area to be drained|
The table is based on a rainfall intensity of 100 mm per hour (4 inches per hour). The anticipated rainfall intensity should always be checked with the local authorities.
The purpose of the sanitary drainage system is to remove effluent discharged from plumbing fixtures and other equipment.
Dimensions of cast iron soil pipes.
Cleanouts provides access to the sewer for rodding.
Capacities of vertical downspouts when draining roof areas in rainfall.
Draining of roof areas and recommended gutter slopes
Convert between different rainfall or storm-water units
Convert slopes pitch between degrees, gradients and grades.
Roof drain capacities.
Storm-water runoff coefficients for various surfaces