The quick answer
Zincalume and Colorbond are closely related. Both are steel sheets protected by an aluminium-zinc alloy coating. Zincalume stops there and keeps a bare metallic finish. Colorbond adds a primer and a baked-on paint system over that same type of coated base. Both are made in a range of profiles, from corrugated to trapezoidal. For most Brisbane re-roofs, Colorbond is the more versatile choice because of colour options and the extra paint layer, but Zincalume remains a sensible, traditional option, particularly for Queenslanders, workers' cottages, sheds and rear extensions.
Side-by-side comparison
| Factor | Zincalume | Colorbond |
|---|---|---|
| Finish | Unpainted silver metallic | Pre-painted, wide colour range |
| Base | Steel with aluminium-zinc coating | Steel with aluminium-zinc coating plus primer and paint |
| Look | Traditional, industrial | Flexible, can suit any style |
| Glare when new | Can be high | Lower, depends on colour |
| Heat reflection | High when new, changes as it weathers | Varies with colour, light shades strong |
| Compatibility cautions | Avoid contact with some metals and run-off | Fewer, still follow manufacturer guidance |
| Character streets | Often matches original iron | Heritage-style colours available |
| Upfront price | Usually lower | Usually higher |
For what drives the overall price of either option, see the roof replacement cost page.
Appearance and street character
Many of Brisbane's timber houses on stumps originally had galvanised corrugated iron. Zincalume gives a very similar silver look, which is why it is still popular on Queenslanders in suburbs such as Paddington, Red Hill and Windsor. Colorbond offers heritage-style colours in corrugated profile too, so painted steel can also sit comfortably in a character street. If your home is in a Brisbane City Council character overlay, check whether colour or finish matters for approval. Our page on regulations and permits explains when an approval is more likely.
Heat and comfort
Brisbane summers are long, hot and humid. A new Zincalume roof reflects a lot of solar radiation, and a light Colorbond colour performs strongly as well. Darker painted colours absorb more heat. In practice, the underlay and ceiling insulation have a large effect on indoor comfort whichever sheet you choose. Reflective sarking or an insulation blanket under the steel, plus good ventilation, can matter as much as the finish. Our article on energy-efficient roof replacement options covers this.
Glare and neighbours
Glare is the main practical drawback of Zincalume. On hilly suburbs such as The Gap, Bardon or Ashgrove, where houses often look down onto each other's roofs, a bright new unpainted roof can be noticeable. The surface dulls over time, but it is worth considering how your roof will look from next door.
Salt air and corrosion
Both products rely on the same type of metallic coating for corrosion protection, and Colorbond's paint adds a further barrier. Near Moreton Bay, in suburbs like Wynnum, Manly, Shorncliffe and Sandgate, salt deposits accelerate corrosion, especially in areas that are not washed by rain, such as under eaves overhangs and on the underside of sheet laps. Check the manufacturer's environment guidance for your distance from the bay or breaking surf, because a different product or steel grade may be recommended. Fixings and flashings should be matched to whatever sheet is chosen.
Compatibility with other materials
This is where Zincalume needs more care. The manufacturer cautions against it touching certain materials, and against water running onto it from some surfaces. Commonly cited examples include:
- Lead flashings or lead-based products.
- Copper pipes, copper flashings, or run-off from copper surfaces such as old hot water units or solar hot water pipework.
- Some treated timbers and wet concrete or mortar in direct contact.
- Water discharging from certain other roof materials or units onto the sheet.
Painted steel also has compatibility guidance, but it is generally more forgiving. Ask your contractor to check every pipe, flashing and fitting on the roof, especially if you are keeping older plumbing or an existing hot water system.
Hail, solar and rainwater
On hail, the two behave much the same, because the steel underneath is the same kind. A heavy storm can dent either one, and dents on a bare silver finish can catch the light a little more. Thicker sheet and closer fixing help in exposed spots.
For solar, both take standard mounting brackets, though the fixing method should suit the profile and follow the panel and roofing manufacturers' guidance. If you collect rainwater for drinking, ask whether the chosen product and any sealants are suitable under the manufacturer's guidance, and keep first-flush diverters in good order. Copper pipework from older solar hot water systems is worth checking again here, since run-off from it onto Zincalume is one of the combinations to avoid.
Maintenance over time
Neither option needs much upkeep. The main tasks are the same:
- Keep gutters and valleys clear so leaves do not trap moisture against the metal.
- Rinse areas not reached by rain, such as under wide eaves, particularly near the bay.
- Remove debris like metal swarf or offcuts after any trade works on the roof.
- Check fixings and flashings after major storms.
Colorbond's paint will slowly fade over many years, and Zincalume weathers from bright silver to a duller grey. Neither change necessarily affects performance.
Which should you choose?
Choose Zincalume if you want the traditional silver look, are re-roofing a Queenslander or outbuilding, have no copper or lead nearby, and glare will not bother neighbours.
Choose Colorbond if you want colour choice, a painted protective layer, less glare, or a finish that blends with modern homes and estates.
If you are still unsure, the contractors we work with can show samples on site. We ask the contractors we work with to hold the licences and insurance the job needs, so ask to see them before work starts. More detail on painted steel is on our Colorbond roofing service page, and wider steel options are covered under metal roof replacement.
General information for Brisbane homeowners, written for planning, not a substitute for someone inspecting your roof. Rules and products change; confirm details with Brisbane City Council, the QBCC or the agency named before acting.