Secondary Roof Scupper Drains

Scuppers shall not have an opening dimension of less than 4 inches.

Secondary roof scupper drains.

Scuppers can be installed to carry water into gutters or directly into downspouts through conductor heads. Scuppers are used to provide an outlet through parapet walls or gravel stops on flat and built up roofs to allow drainage of excess water. Where roof drains are required secondary emergency overflow roof drains or scuppers shall be provided where the roof perimeter construction extends above the roof in such a manner that water will be entrapped if the primary drains allow buildup for any reason. 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.

See section 1107 for yourself. Providing an immediately adjacent secondary overflow drain next to every primary drain with a separate piping system. It s very short and to the point. This is why overflow scuppers are just holes in the wall without a conductor head and downspout.

Your view of overflow scupper openings should be unobstructed. They can be used in conjunction with gutters and downspouts to divert the flow to the desired location. But if interior roof drains are your primary and the scuppers are your secondary drainage system you do want to see this because it lets you know that your drains are clogged. The better choice if it can be accommodated is one of the first two methods where overflow at the exterior of the building roof is provided without the need for secondary drainage piping.

Scuppers shall not have an opening dimension of less than 4 inches. Secondary emergency roof drains or scuppers are required according to ipc to prevent a rainwater build up. The secondary roof drains can be of two types roof drains with an independent piping system or roof drains that combine with the primary roof drainage piping which will require an increase in piping size. Firstly there is an explanation in the above referenced section for where and why a secondary roof drainage system must be provided.