A rainhead or sump is a container located between the gutter and downpipe that aids the flow of water away from the roof.
Box gutter sump installation.
Layout box gutters must.
If you have any questions about the vid.
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.
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.
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.
Beowulf builders bringing old homes into the future this video explains how you go about installing a boxed gutter.
If the box gutter has no overflow provisions this causes a waterfall over the sides of the box gutter typically running down the walls.
At this stage plan the connection to the downpipe.
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.
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.
The side with the maximum flow is used to size the box gutter.
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.
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.
Outlets box gutter outlets must discharge through either a rainhead or sump.
It sounds like you have an overflow situation.
For the associated box gutter outlet.
Establish the sump location this should be the lowest point in the box gutter.