Roof Scupper Sizing

Table d104 1 lists the discharge capacity of rectangular roof scuppers of various widths with various heads of water.

Roof scupper sizing.

Scuppers shall not have an opening dimension of less than 4 inches. The maximum allowable level of water on the roof shall be obtained from the registered design professional based on the design of the roof. Calculator notes and assumptions. Rainfall wizard is based on table 1 2 rainfall data and drainage factors page 1 2 1 3 of the architectural sheet metal manual 7th edition.

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. Determine 100 year 1 hour rainfall rate used for location of building. For the purposes of this appendix the following metric conversions are applicable. Calculator is based on chapter 1 of smacna s architectural sheet metal manual 7th edition asmm.

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. 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. 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. Factors which affect proper roof drainage are deck slope drain size and placement of drains.

Size horizontal storm drainage piping. Ipc provides four steps to size the roof drains on a building. Size vertical storm drainage piping. Select number of roof drains and calculate the roof area sloped to each drain.

If you re looking for technical guidelines for sizing and locating scuppers fm global s ds 1 54 roof loads for new construction data sheet is an excellent resource see the link below. 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.