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.
Box gutter sump size.
Colorbond box gutter measures 150mm x 150mm x 150mm.
Sumps can be made to order but are commonly manufactured in either 100mm and 150mm depths.
Flow as the down pipe.
Overflow devices need to discharge to the atmosphere in such a way as to prevent damage to buildings and property.
How much fall should i have on a box gutter.
The outlet must be no further than the diameter of the outlet to the centre of the outlet.
The rectangular overflow width is equal to the box gutter width less 100mm.
The code sump length is 600mm.
Deviations from the gradient must be smooth and prevent towards the outlet without a proportional permanent ponding.
This will give a sump depth about 150mm.
The minimum size of a sump is 400mm x 200mm minimum width of box gutter and 150mm deep.
If this is the case the sump length will increase to accommodate the downpipe.
They collect storm water before it is carried away by the downpipe and they also serve to catch any debris before it enters the downpipe.
Learn more how to storm water design for building sites.
The suggested down pipe diameter is shown for reference purposes only.
Sumps are usually attached between a box gutter and the downpipe.
A box gutter is given its name as it is usually boxed into the middle or edge of the roof.
50mm clearance on both sides.
Choose an available dp size or any other size and enter that for the calculation of the sump.
Downpipe eaves gutter long straight eaves gutters box gutter to rain water head box gutter vertical faces box gutter side o flow box gutter vertical o flow storm water pipe size storm water network overland flow path spitter upstream end custom rain water head.
The depth shown of the box gutter is the depth at the upstream end.
However if you choose to go above 16l s the downpipe may get larger than 150 dia.
Experiment with this figure to get the depth of box gutter you require.
Trial box gutter width the minimum width allowed for commercial projects is 300mm for domestic projects 200mm.
The overflow diameter is the same as the downpipe diameter.
If draining to a sump with a vertical overflow in the middle of the box gutter use this calculator.
Box gutter gradients shall not be flatter than 1 200 for sole widths equal to or less than 600mm wide.
