Roof Scupper Sizing

Determine 100 year 1 hour rainfall rate used for location of building.

Roof scupper sizing.

Section 1503 4 2 scuppers 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. The full flow capacity of a drain is not realized until the water reaches approximately 2 5 above the inlet in a four inch drain and 3 5 in a six inch drain. This wizard makes it easy to calculate the roof design area by providing various shape calculations and the calculation for vertical walls area per international plumbing code ipc. Size horizontal storm drainage piping.

Select number of roof drains and calculate the roof area sloped to each drain. Calculator is based on chapter 1 of smacna s architectural sheet metal manual 7th edition asmm. Roof drain system and size the scuppers denoting the required head of water above the scupper for the structural engineer. Factors which affect proper roof drainage are deck slope drain size and placement of drains.

For the purposes of this appendix the following metric conversions are applicable. Table d104 1 lists the discharge capacity of rectangular roof scuppers of various widths with various heads of water. Size vertical storm drainage piping. Calculator notes and assumptions.

2014 fbc building 5 th edition 15 roof assemblies and rooftop structures 1514 high velocity hurricane zones weather protection 1514 4 roof drainage 1514 4 2 overflow drains and scuppers 1108 3 storm drainage sizing of secondary drains. 1 in 25 4 mm 1 ft 305 mm 1 ft2 0 0929 m2 100 0 figure a101 1 example roof plan 4 a 101 2 solution. Ipc provides four steps to size the roof drains on a building. Smacna s new downspout and gutter sizing calculator enables the user to manually enter the design area of the roof or use the design area wizard for the calculation.

The maximum allowable level of water on the roof shall be obtained from the registered design professional based on the design of the roof. If you do know the diameter of the properly sized drain for your roof area however you can calculate the size of the equivalent scupper from that.