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.
Box gutter sump design.
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 total flow is used to size the sump and overflow.
This is a video of a google slides presentation available here https docs.
Overflow box gutters must have independent overflow provision discharging to the atmosphere.
Box gutter with rain water head at end of box gutter.
Or c a sump with a high capacity overflow device.
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.
Establish the sump location this should be the lowest point in the box gutter.
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.
All of the above options provide overflow provision to the box gutter.
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.
The hydraulic capacity of these overflow devices must not be less than the design flow for the associated gutter outlet and must discharge to the atmosphere.
Layout box gutters must.
How to design box gutters to the australian plumbing code as nzs 3500 3 2015.
A sump with a high capacity overflow device.
Sumps are attached between a box gutter and a downpipe where they collect stormwater before sending it down the downpipe.
Simplified suitable for flattish roofs with little or no vertical faces or steep roofs draining to one side of box gutter only or any roof if you are in a hurry and make the necessary allowances for all catchments.
Rainheads are an essential design element for buildings where internal box or trough gutters are used.
A a rainhead b a sump with a side overflow device.
Sumps made in colorbond zincalume will be riveted and silicone.
Stainless steel galvanized will be soldered not siliconed.
Safe trays are useful in a variety of building applications.
To avoid problems plumbers need to calculate the hydraulic capacity of a box gutter and when designing overflow devices consider whether the discharge of the box gutter is to.