Dirt tends to accumulate in the box gutter.
Box gutter sump guards.
However by definition to have a sump somewhere along the gutter implies that there will be flow approaching the sump from two sides.
At this stage plan the connection to the downpipe.
The side with the maximum flow is used to size the box gutter.
Refer to hints for box gutter design marking and cutting the sump spigot mark cut sump hole dress the cut out to neatly fit to the sump decide on the position of the spigot mark and cut the hole.
Box gutter slope slope should be within the range of 1 40 to 1 200.
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.
It is usually advisable to install a sump guard protector with an overflow fitted to it so as you can also insure against foreign material flowing down the downpipes and minimizing a blockage in the downpipe or the storm water thus elevating the chances of a flow into the building of water egress.
Overflow devices need to discharge to the atmosphere in such a way as to prevent damage to buildings and property.
Rainheads are an essential design element for buildings where internal box or trough gutters are used.
The side with the maximum flow is used to size the box gutter.
A rainhead or sump is a container located between the gutter and downpipe that aids the flow of water away from the roof.
It acts as an external overflow point to reduce water surges into the stormwater system and aid the flow of water down.
Establish the sump location this should be the lowest point in the box gutter.
The total flow is used to size the sump and overflow.