However any width can be entered.
Box gutter sump regulations.
Box gutters must be straight no bends.
This will prevent water damage in the event of gutters overflowing either due to high rainfall or a blockage.
Down pipe must be vertical from sump not to the side minimum sump length is 400mm.
Experiment with this figure to get the depth of box gutter you require.
The regulations require that guttering has allowances for water to overflow gutters in a way that does not cause water to flow back into the structure.
Have a minimum width of 300mm for commercial installations 200mm for domestic installations.
State of victoria victorian building authority 2017 published june 2017.
Sumps are to be appropriately sized in accordance with as nzs 3500 3 with a minimum length of 400 mm and when fitted with a high capacity overflow device with a depth of not less than 150 mm when either one or two box gutters enter the sump.
Must have a constant slope between 1 40 and 1 200.
For commercial projects the minimum allowable width is 300mm.
Sump with a side overflow device sumps do require an increase in the depth of flow in the box gutter and gutters are to be fitted with either.
Have a minimum depth of 75mm at the high end.
Have a sole width which is not reduced discharge at the downstream end without.
The minimum size of a sump is 400mm x 200mm minimum width of box gutter and 150mm deep.
Sizes the depth shown of the box gutter is the depth at the upstream end.
Sides must be vertical.
For the associated box gutter outlet.
Overflow devices need to discharge to the atmosphere in such a way as to prevent damage to buildings and property.