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RAIN LOADS AND PONDING

Design Parameters

Design Rainfall Intensity i = 38 mm/h

Inlet of Secondary Roof scuppers/drain r = 51 mm

Roof area serviced y a single drainage system! in m" # = 1$%&'$"5 m"

(lo) Rate * = $'"+8,1$-%#i m3/s

.Secondary drainage 3$5mm )ide channel scupper

* = $'$11"&318$1 m3/s

ds = 51 mm

dh = +% mm

Design rain load R = 5'" .dh0ds

R = "% psf  

Static head .depth of )ater

from the scupper inlet to the roof surface

ydraulic head! dh2sing 4ales 8-1 and 8-"! y interpolation!the 6o) rate for a 1" in' .3$5 mm )ide channelscupper is t)ice that of a % in' .15" mm )idechannel scupper' sing 4ales 8-1 and 8-"! thehydraulic head! dh! for one-half the 6o) rate! *! or&$ gal/min .$'$$5+ m3/s! through a % in' .15" mm)ide channel scupper is 3 in' .+% mm'

dh = 3 in' .+% mm for a 1" in' )ide .3$5 mmchannel scupper )ith a 6 o) rate! *! of .$'$113 m3/s'

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8-1 Ref' #S7+ 1$

" in

3 in

1'" 9/m"

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