Each box gutter run must discharge independently to ether a sump or directly out of the building without changing the size of the gutter or changing direction.
Box gutter sump size.
With building design being so restrictive on space these days this is the area where designers must think about how the roofing contractor will make the box gutter comply.
Support the entire weight of the gutter and sumps when full of water as well as a trafficable load at any point in the gutter and sumps.
This free online box gutter calculator will calculate the size of box gutters and sumps with a side overflow in accordance with the australian plumbing code as nzs 3500 3 2003 part 3 storm water drainage.
Layout box gutters must.
This is best done by your architect engineer or building designer and should conform to the requirements of as nzs 3500 3 2003 plumbing and drainage.
The total flow is used to size the sump and overflow.
Overflow box gutters must have independent overflow provision discharging to the atmosphere.
The side with the maximum flow is used to size the box gutter.
When determining the size of your rainhead you will need to consider such things as rainfall intensity occurrence use of the building and the size of the box gutter.