Colorbond Downpipes Accessories

In most cases — yes. Under Victorian building regulations and the Plumbing Regulations 2018, rainwater from your roof must be directed to an approved stormwater drainage system. This typically means your downpipes need to connect to the council’s stormwater network, a rainwater tank, or a soakage pit that meets local requirements. Simply letting water flow onto the ground or a neighbour’s property is not allowed and can cause serious drainage and erosion problems. If you’re unsure about the rules for your property, your local council or a licensed plumber can advise you. 

Yes — but it needs to connect to something approved underground. A downpipe can go straight into the ground if it connects to a stormwater pipe, soakage pit, or rainwater tank system. In Victoria, you generally can’t just let the water soak into the soil without proper drainage infrastructure, especially in areas with clay-heavy soils (common in Melbourne’s suburbs) where waterlogging can damage foundations. For homes on large blocks in rural Victoria, an agricultural drain or large soakage trench might be acceptable — but always check with your local council first. Your downpipe shoe (the curved fitting at the bottom) and any underground connection fittings need to match your pipe size. We stock all the accessories you need to finish the job properly. Browse our full range of downpipe accessories at Singh Roofing Supplies to find the right fittings for your setup.

In many cases — yes, a confident DIYer can replace a downpipe themselves. Replacing like-for-like (same size, same connection type) is usually a straightforward job. You’ll need to: remove the old clips and pipe sections, cut the new Colorbond downpipe to length, reattach it using matching downpipe clips, and reconnect it at the top (gutter outlet) and bottom (shoe or underground connection). However, if the job involves connecting to underground stormwater pipes or making changes to your drainage layout, Victorian law requires a licensed plumber for that part of the work. Always use the correct matching Colorbond® colour so your new pipe blends seamlessly with your existing gutters and fascia.

The life expectancy of a downpipe depends on the material it’s made from. Basic PVC downpipes typically last 20–30 years before they become brittle, crack, or fade. Galvanised steel downpipes can last around 20–40 years, but they rust over time — especially in coastal areas like the Mornington Peninsula or Geelong. Colorbond® steel downpipes, on the other hand, are built to last much longer thanks to their multi-layer protective coating and Activate® technology. BlueScope warrants Colorbond® steel against corrosion for up to 36 years and against paint flaking or peeling for up to 20 years from the date of installation.

Choosing the right downpipe size depends on two main things: how big your roof is and how much rainfall your area gets. Victoria’s weather varies a lot — Melbourne’s CBD gets around 650mm of rain per year, while areas like the Dandenong Ranges can get over 1,200mm annually. A bigger roof area or higher rainfall zone means you need a larger downpipe to handle the water load without overflowing.

As a general guide for Victorian homes:

• 100×50mm rectangular or 75mm round — suits most standard residential homes with a typical roof area
• 100×75mm rectangular — better for larger roofs, multi-storey homes, or areas with heavy rainfall
• One downpipe is generally recommended for every 40–50 square metres of roof catchment area

If your gutters are overflowing during heavy rain, that’s a clear sign your current downpipes are either the wrong size or there aren’t enough of them. Upgrading to a larger Colorbond downpipe — or adding an extra one — is usually the most cost-effective fix.