Box Gutter Regulations

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.

Box gutter regulations.

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. The side with the maximum flow is used to size the box gutter. A box gutter internal gutter parallel gutter or trough gutter is a rain gutter on a roof usually rectangular in shape. This will prevent water damage in the event of gutters overflowing either due to high rainfall or a blockage.

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. Peter coll provides a timely update regarding the provision for overflow and box gutter compliance. Box gutters are becoming well recognised as a problem area for plumbers to design and install. Architects draftpersons builders and other practitioners responsible for designing a box gutter should work closely with the roof plumbers that will install the box gutter to ensure that the overall design and installation will be compliant with relevant regulations.

The ahsca is looking to rectify the issue with targeted training. Installing box gutters to achieve compliance with relevant regulations. The outlet of the box gutter may be blocked by debris or the box gutter outlet simply cannot discharge the water fast enough. It sounds like you have an overflow situation.

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. It is at the layout of the design stage that compliance failure of box gutter usually begins. Box gutters are essentially placed between parallel surfaces as in a valley between parallel roofs or at the junction of a roof and. 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.

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.