The sole width of the box gutter is not to be reduced towards the outlet without a proportional increase in depth.
Box gutter sump depth.
The theoretical down pipe diameter is shown for reference purposes only.
Have a minimum depth of 75mm at the high end.
All domestic box gutters must be a minimum of 200mm wide and 75mm deep.
Discharge through either a rainhead or sump.
2015 3 7 4 layout e for the sump high capacity overflow device the depth of the sump hs shall be not less than 150 mm regardless of the position of the normal outlet.
This is a good size for the required flow.
Choose an available size or any other size and enter that for the calculation of the sump.
Have a sole width which is not reduced discharge at the downstream end without.
Choose an available dp size or any other size and enter that for the calculation of the sump.
Have a minimum width of 300mm for commercial installations 200mm for domestic installations.
This will give a sump depth about 150mm.
The suggested down pipe diameter is shown for reference purposes only.
The depth shown of the box gutter is the depth at the upstream end.