Box gutters must be straight no bends.
Box gutter sump.
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.
The depth shown of the box gutter is the depth at the upstream end.
Must have a constant slope between 1 40 and 1 200.
Down pipe must be.
This is a good size for the required flow.
Code box gutter requirements the minimum width allowed for domestic projects is 200mm.
The theoretical down pipe diameter is shown for reference purposes only.
For the associated box gutter outlet.
It is easier to mark and cut the spigothole prior to fitting the sumpinto the box gutter.
The minimum size of a sump is 400mm x 200mm minimum width of box gutter and 150mm deep.
Overflow devices need to discharge to the atmosphere in such a way as to prevent damage to buildings and property.
For commercial projects the minimum allowable width is 300mm.
Sides must be vertical.
The outlet must be no further than the diameter of the outlet to the centre of the outlet.