Roof Drain Overflow Scupper

A primary drainage system is designed to remove water from the roof as quickly as possible.

Roof drain overflow scupper.

When scuppers are used for secondary emergency overflow roof drainage the quantity size location and inlet elevation of the scuppers shall be sized to prevent the depth of ponding water from exceeding that for which the roof was designed as determined by section 1611 1. While you must provide the overflow it can not be connected to a downspout. Scupper building drainage zurn scupper roof drains from zurn manufactures a variety of sizes and finishes. Scuppers shall not have an opening dimension of less than 4 inches.

Cast options ranging from iron to stainless steel. Where you must drain through the wall with a scupper the overflow must be three times the required size of the roof drain and have a minimum height of 4 and again be installed no more than 2 above the roof low point. In short a scupper is a detail that provides drainage to a roof system by allowing the water runoff from the roof to exit the roof through a metal edge parapet wall or through the deck into a downspout or leader not run through the interior of the building. They will either be a part of the primary drainage system or they will be a part of the secondary overflow drainage system.