Overflow Roof Drain Requirements

A good rule to follow is to provide two roof drains for a total roof area less than 10 000 square feet.

Overflow roof drain requirements.

1106 6 size of roof gutters horizontal gutters shall be sized based on the flow rate from the roof surface. Parapet wall roof drainage scupper and overflow scupper location shall comply with the requirements of section 1503 4 of the florida building code building. U flow roof drain mercial roof drains pvc abs and cast iron roof drainage systems duro last roofing inc green roof metered overflow drain grd 640 watts powered by. Local codes vary but it is recommended to provide a 1 to 1 ratio roof load the maximum possible rainwater build up load should be determined and provided to the structural engineer for inclusion in the roof structure design.

An additional roof drain should be added for each 10 000 square foot area. Wade 3042 13 in bo roof and roof and overflow drain one piece bo overflow roof drain overflow roof drain with 2 in external. The flow rate in horizontal gutters shall not exceed that specified in table 1106 6. The bottom edges of the overflow scuppers that you see on existing buildings today will almost always be about two inches above the adjacent roof surface.

Desired rate of drainage safety overflow requirements emergency secondary overflow roof drains are recommended. This is to prevent overflow scuppers from acting as primary drains. Overflow drains shall be the same size as the roof drains with the inlet flow line two inches above the low point of the roof and shall be installed independent from the roof drains. 1106 6 size of roof gutters horizontal gutters shall be sized based on the flow rate from the roof surface.

By the 1997 edition of the upc section 1101 11 2 had been added that completely prescribed where and how secondary roof drainage was to be provided. The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process. Drainage requirements once the drainage system is determined the designer must ensure positive drainage by correctly positioning the roof drains. 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.

Roof overflow drain requirements.