Dowin Engineering Comstrucion Pvt. Ltd.

Overflow devices are critical to a box gutter installation. Failing to install appropriately sized and positioned overflow devices can lead to serious damage to buildings and contents, often resulting in high-cost insurance claims. The Plumbing Code of Australia (PCA) Vic Part E3 sets out the Performance Requirements to safeguard people from illness, injury or loss (including loss of amenity) due to the failure of a roof drainage installation. Compliance with these requirements can be demonstrated through either a Performance Solution or a deemed-to-satisfy solution, however, roof drainage systems that are designed and installed in accordance with AS/NZS 3500.3 and SA HB:39 are automatically deemed-to-satisfy these requirements. Where a Performance Solution is used as the compliance pathway, the solution must demonstrate that the box gutter’s functionality is at least equivalent to it’s deemed-to-satisfy alternative. This will ensure that the box gutter, downpipe, and overflow sizing has sufficient hydraulic capacity and freeboard to prevent wind driven spillages and overtopping from occurring within the building’s footprint in the event of a total downpipe blockage.