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 regulations.
Installing box gutters to achieve compliance with relevant regulations.
This has become a big issue in the past few months particularly in victoria and is going to be a new section in the upcoming.
Box gutter design and compliance is detailed in plumbing regulations sa hb 39 installation code for metal roof and wall cladding as well as saa snz hb 114 guidelines for the design of eaves and box gutters.
The regulations require that guttering has allowances for water to overflow gutters in a way that does not cause water to flow back into the structure.
In my last article i discussed the emergence of the issue of provision for overflow in external eaves gutters or more specifically the lack of provision for overflow.
Box gutters are becoming well recognised as a problem area for plumbers to design and install.
It is at the layout of the design stage that compliance failure of box gutter usually begins.
It sounds like you have an overflow situation.
The total flow is used to size the sump and overflow.
If the box gutter has no overflow provisions this causes a waterfall over the sides of the box gutter typically running down the walls.
The ahsca is looking to rectify the issue with targeted training.
It may be lined with epdm rubber metal asphalt or roofing felt and may be concealed behind a parapet or the eaves or in a roof valley.
The outlet of the box gutter may be blocked by debris or the box gutter outlet simply cannot discharge the water fast enough.
In the summer 2017 edition of plumbing connection we highlighted that box gutter rainheads are a problematic aspect of gutter design extending from the designer to the installer and the inspector.
The side with the maximum flow is used to size the box gutter.
Box gutters are essentially placed between parallel surfaces as in a valley between parallel roofs or at the junction of a roof and.
This will prevent water damage in the event of gutters overflowing either due to high rainfall or a blockage.
