When should overflow scuppers be used?
1 Secondary (emergency overflow) drains or scuppers. 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.
How do you size a scupper?
The only unconditional guideline for roof scupper sizing provided by the code is that “scupper openings shall be not less than 4 inches (102 mm) in height and have a width that is equal to or greater than the circumference of a roof drain sized for the same roof area.”
What is an overflow scupper?
Overflow drainage scuppers are typically holes with no downspout or other intricate designs. This is because these scuppers are specifically designed to remove water when there is a blockage in the primary system. Overflow drains can be used with roof drains or with primary drainage roof scuppers.
How much rainwater can a 4 pipe handle?
Example: For a 4″ hourly rainfall and 4″ leader, each drain can handle 4,600 sq. ft. of roof area.
How many roof drains do I need?
Take the roof’s total square footage and divide by the total square footage handled by one drain. The result is the number of drains needed. For example: 50,000 / 4,400 = 11.36; or 12 drains required.
How far apart should scuppers be?
Scuppers should be spaced no greater than 10 feet apart depending on the roof area drained.
How high should overflow scupper be?
The area of the scupper shall be three times the area of that required for the drain, with a minimum vertical dimension of 4 inches (102 mm). The lower edge of the overflow scupper opening shall be 2 inches (51 mm) above the roof drain.
How do you calculate roof drain size?
What is the height of an overflow drain above a roof drain?
Overflow drains, located 2 inches (51 mm) above the roof drain inlet, are required by Section 1506.3 where parapets or other conditions will cause ponding if the roof drain is inoperative.
How many gallons of water can flow through a 4 inch pipe?
Water Flow Capacity in Steel Pipes (sch 40)
|Pipe Size||Maximum Flow (gal/min)||Head Loss (ft/100 ft)|
How much water can flow through a 4 inch PVC pipe?
Metric PVC Pipe
|Assume Average Pressure. (20-100PSI) About 12f/s flow velocity|
What is the minimum number of roof drains for any size building?
Not less than two roof drains shall be installed in roof areas 10,000 square feet (929 m2) or less and not less than four roof drains shall be installed in roofs over 10,000 square feet (929 m2) in area.