Downpipe Sizing Guide for Torrential Coastal Storms
South-East Queensland’s intense summer thunderstorms and coastal downpours can overwhelm roof drainage that is undersized, poorly positioned or blocked. Correct downpipe sizing protects more than gutters: it helps prevent water entering eaves, wall cavities and foundations. The right size depends on rainfall intensity, the roof area feeding each outlet and the capacity of the entire drainage system. What Determines the Right Downpipe Size? A suitable downpipe canno