Design Calculation Sheet: Roof Drain Vertical Leader Requirements For Horizontal Roof Areas at Various Rainfall Rate
Design Calculation Sheet: Roof Drain Vertical Leader Requirements For Horizontal Roof Areas at Various Rainfall Rate
Design Calculation Sheet: Roof Drain Vertical Leader Requirements For Horizontal Roof Areas at Various Rainfall Rate
A x R x 0.0104
GPM = 6383 0.75 x 0.0104 => GPM = 49.8
A x R / 3600
L/S = 593 x 19.05 / 3600 => L/S = 3
Selection :
ALLOWABLE FLOW
Horizontal Storm Drain Slope per Foot
Pipe Size Vertical Leaders 1/8" (1%) 1/4" (2%) 1/2" (4%)
Inches mm GPM L/S GPM L/S GPM L/S GPM L/S
2" 50 30 2 12 1 17 1 24 2
3" 82 90 6 36 2 51 3 72 5
4" 110 192 12 78 5 111 7 157 10
5" 125 348 22 142 9 201 13 284 18
6" 150 566 36 231 15 327 21 462 29
8" 200 1220 77 498 31 705 44 996 63
10" 250 2200 139 902 57 1275 80 1804 114
12" 300 - - 1467 92 2076 131 2934 185
15" 375 - - 2666 168 3774 238 5332 336
Table 2
No. or risers required = 4