Australian National Construction Code - Gutter & Downpipes

The Australian National Construction Code (NCC) sets out the minimum requirements for the design and construction of buildings in Australia. Part 3.5.2 of the NCC provides specific requirements for gutter and downpipe systems in order to ensure adequate drainage and prevent water damage to buildings.

The NCC specifies that gutters and downpipes must be designed and installed to withstand the maximum rainfall intensity for the area in which the building is located. This varies depending on the region and can range from 50mm to 150mm per hour.

Additionally, the NCC sets out requirements for the minimum size of gutters and downpipes, based on the roof area and expected rainfall intensity. For example, a roof area of 100 square meters with an expected rainfall intensity of 90mm per hour requires gutters with a minimum cross-sectional area of 125mm² and downpipes with a minimum diameter of 90mm.

The NCC also specifies the minimum slope for gutters to ensure effective drainage, and requires that gutters and downpipes be securely fixed to the building structure to withstand wind and other loads.

By adhering to the gutter and downpipe requirements set out in the NCC, builders and homeowners can ensure that their buildings are adequately protected against water damage and meet the minimum standards for building construction in Australia.