1106 6 size of roof gutters horizontal gutters shall be sized based on the flow rate from the roof surface.
Overflow roof drain requirements.
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.
The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures.
To prevent dangerous building loading or even structural collapse roof drainage systems using an internal or piped roof drain system should provide for overflow drains to handle excess water volume and weight loading should the roof drainage system become blocked or prove inadequate in unusual conditions.
Desired rate of drainage safety overflow requirements emergency secondary overflow roof drains are recommended.
The flow rate in horizontal gutters shall not exceed that specified in table 1106 6.
This is to prevent overflow scuppers from acting as primary drains.
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 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.
An additional roof drain should be added for each 10 000 square foot area.
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.
Parapet wall roof drainage scupper and overflow scupper location shall comply with the requirements of section 1503 4 of the florida building code building.
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.
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.
A good rule to follow is to provide two roof drains for a total roof area less than 10 000 square feet.
Roof overflow drain requirements.
Parapet wall roof drainage scupper and overflow scupper location shall comply with the requirements of section 1503 4 of the international building code.
1106 6 size of roof gutters horizontal gutters shall be sized based on the flow rate from the roof surface.
