Roof Area (Sq.m)
Peak Hourly Rainfall (mm)
Roof Slope
Pipe Dia (mm)
| Total Roof Drains Required | ||
|---|---|---|
Slope
- 0.5 % grade = 0.5 cm per 100 cm run = 0.0625 inch per 1 ft run
- 1 % grade = 1 cm per 100 cm run = 0.125 inch per 1 ft run
- 2 % grade = 2 cm per 100 cm run = 0.250 inch per 1 ft run