Ibc Roof Drain Sizing

Part two of this inspection guide can be accessed from this page.

Ibc roof drain sizing.

In a roof drainage system you have many components. The rain storm the flow of rainwater on the roof surface the ability of the roof drain to move the water from the roof to the piping the vertical piping the horizontal piping and the connection to the point. 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. The sizing of the roof drainage system must consider all components.

Rates of rainfall for various cities on the icc website provides the rainfall data for major us cities. Each 4 drain size in a 6 hourly rainfall area will accommodate drainage of 3 070 sq. Calculate drains needed. Roof drainage systems part 1 at the international association of certified home inspectors website is worth taking a look at.

That is what is wrong. The flow rate used for sizing the storm drainage piping shall be based on the maximum anticipated ponding at the roof drain. 4 select a reference of a roof drain size with hourly rainfall together with the roof area square footage you have estimated and then determine from the chart below how many roof drains you require. The above sizing data is offered as a guide only.

This table is based on zurn s roof drain vertical requirement for horizontal roof areas at various rainfall rates table. The result is the number of drains needed. 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. Factors which affect proper roof drainage are deck slope drain size and placement of drains.

Determine 100 year 1 hour rainfall rate used for location of building. Size horizontal storm drainage piping. 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. The pipe sizing is only one component.

Inspection of roof drainage systems. Take the roof s total square footage and divide by the total square footage handled by one drain. Ipc provides four steps to size the roof drains on a building. Select number of roof drains and calculate the roof area sloped to each drain.