Colorbond vs Galvanised Steel for Flat Roofs in Victoria: Which Is the Better Long-Term Investment?
If you’re planning to reroof a flat-roof home in Victoria, you’ve likely encountered a significant question: should you opt for Colorbond or galvanised steel? It’s something homeowners ask me all the timeand the answer really depends on your goals and budget.
Here’s a quick breakdown to help you get a head start:
Cost: Galvanised steel is cheaper upfront, usually around A$60–80 per square metre. Colorbond sits higher at A$90–120 per square metre.
Durability: Colorbond generally lasts longer—30 to 45 years with minimal fuss. Galvanised steel tends to need more upkeep and may only last 15 to 25 years, especially in coastal or damp areas.
Weather Protection: Colorbond is designed to handle tough Aussie conditions. It resists corrosion, handles thermal movement better, and performs well in both bushfire zones and coastal areas.
Appearance and Resale: Colorbond comes in a wide range of colours and has a clean, modern look that can boost the value of your home. Galvanised steel has a more industrial finish and may not offer the same visual appeal.
So, if you’re looking for something that’s going to last, look great, and require less maintenance over time, Colorbond is usually the better choice. But if you’re working with a tighter budget or need a short-term solution, galvanised steel could still do the job.
In this guide, I’ll walk you through the pros and cons of each material, not just from the specs on paper but from real-life experience installing both across Victoria. Let’s get into it.
Cost Comparison
Let’s start with the numbers.
On average, Colorbond roofing costs between $90 and $120 per square metre installed, depending on the profile and colour. Galvanised steel usually comes in at a lower cost, around $60 to $80 per square metre installed. So, if you’re looking at the upfront cost alone, galvanised steel is the obvious choice.
But here’s where it gets important. The real cost of a roof isn’t just what you pay on the day of installation. You also need to consider ongoing maintenance and the lifespan of each material, as well as the frequency of repairs or replacement required.
Galvanised steel is more prone to rust, especially on flat roofs where water can sit for longer. Over time, you may need to apply rust treatment, make spot repairs, or even repaint sections to maintain their appearance and functionality. These costs can creep up on you, especially in coastal or humid parts of Victoria.
Colorbond, on the other hand, is made with a pre-painted, corrosion-resistant coating designed to withstand tough Australian conditions. It typically needs little to no maintenance for the first 20 years or more. That makes a significant difference over the long term, both in terms of cost and in terms of peace of mind.
So, while galvanised steel might save you a few thousand dollars upfront, Colorbond often ends up being cheaper in the long run because it holds up better and doesn’t need constant attention.
Longevity and Durability
When it comes to the longevity of a roof, I always tell clients that this is where the real value of their investment is most evident. In my experience working on flat roofs across Victoria, Colorbond outperforms galvanised steel in both lifespan and resistance to wear and tear.
Colorbond is designed for Australian conditions. It features a baked-on finish that resists chipping, flaking, and blistering, and it withstands well in areas with high exposure to sun, wind, and rain. It’s also corrosion-resistant, which is especially important for flat roofs where water drainage is slower. On average, a properly installed Colorbond roof can last 30 to 45 years with minimal maintenance.
Galvanised steel, on the other hand, tends to show signs of ageing sooner. It’s more vulnerable to corrosion, especially in coastal or humid areas or when the roof doesn’t have a good fall for water runoff. Over time, rust can develop, weakening the material and potentially leading to leaks or structural damage if not addressed promptly. You can expect a lifespan of 15 to 25 years, although regular maintenance may help extend it slightly.
Another thing to consider is thermal movement. Colorbond handles temperature changes better than galvanised steel. It expands and contracts more evenly, which reduces the risk of warping or stress fractures in the sheets over time.
In short, if you want a roof that will last for decades with minimal fuss, Colorbond is the more reliable option. It gives you peace of mind and saves you the cost and hassle of patch jobs down the line.
Maintenance Needs
From what I’ve seen on the job, the maintenance side of things is where Colorbond really shines compared to galvanised steel.
Colorbond is almost completely hands-off for the first 15 to 20 years. It has a pre-painted, baked-on finish that protects against rust, fading, and general weather damage. Please give it a light clean now and then to remove dirt or debris, but that’s about it. If it’s installed correctly with proper fall and flashing, it remains in great shape for decades with minimal effort.
Galvanised steel is a different story. It can look good initially, but it’s much more prone to rust, especially around fasteners, edges, and areas where water can pool — which is common on flat roofs. Over time, you’ll likely need to treat rust spots, repaint sections, and check for corrosion more often. Once rust takes hold, repairs can become urgent and expensive.
I always tell clients that galvanised steel can work well if you’re prepared to stay on top of the upkeep. But if you want to install your roof and not have to think about it again for years, Colorbond is a smarter choice.
Resale Value and Aesthetic Appeal
Whether you’re thinking of selling soon or not, it’s always smart to consider how your roof affects the value of your home.
Colorbond adds to the appeal. It has a clean, modern look, comes in a wide range of colours, and gives buyers the impression that the home has been built or renovated with quality in mind. A Colorbond roof is often seen as a premium feature in newer suburbs and higher-value areas.
Galvanised steel has a more traditional or industrial look. In some cases, it suits the style of the home, but in newer developments or renovated areas, it can give off a more “budget-friendly” feel. That doesn’t necessarily harm the resale value, but it won’t boost it as much as a Colorbond roof might.
From what I’ve seen in real estate, homes with Colorbond roofs are often easier to market and may attract a higher sale price, especially if the roof still looks fresh and well-installed.
Local Considerations in Victoria
Victoria’s climate presents a few additional considerations when selecting roofing materials.
We receive plenty of rain, and we’re also known for experiencing significant temperature swings, even within the same day. Colorbond handles this well. It expands and contracts smoothly with heat, which means fewer issues with movement or fatigue over time. Galvanised steel doesn’t cope as well and can suffer from early wear in these conditions.
If you’re near the coast, galvanised steel can be a risk. Salt air accelerates corrosion, particularly on low-slope roofs. Colorbond offers specific products, such as Colorbond Ultra, designed to withstand environments with high salt content, which I recommend for coastal properties.
And if you’re in a bushfire-prone area, Colorbond performs better, too. It has a higher Bushfire Attack Level (BAL) rating, which means it offers more protection under Australian standards. That alone can make it a requirement in some areas, depending on your location and council rules.
Frequently Asked Questions
It’s not recommended. Proper installation requires experience with flashing, fall angles, and thermal movement. Always use a licensed roofing contractor.
Check for standing water after rain and look for signs of sagging or water marks inside. A professional can inspect and adjust the fall if needed.
Yes. Colorbond offers a range of matte and textured finishes for a more modern or architectural look.
Yes, but it needs the right preparation and paint type to prevent peeling or rust bleeding.
Conclusion
Ultimately, the right roofing material comes down to what matters most to you. If you’re looking for something low-maintenance, long-lasting, and adds value to your home, Colorbond is the smarter long-term investment. It costs more upfront but pays for itself in performance, durability, and peace of mind.
Galvanised steel can still be a good choice if you’re working on a tight budget or need a quick fix, but it will likely require more attention and maintenance over the years, especially on flat roofs in Victoria’s climate.
As a contractor, I always recommend looking beyond just the price per square metre. Consider how the material will withstand water, heat, and the passage of time. A roof is a big part of your home’s structure and comfort, so it’s worth choosing something that will serve you well into the future.
If you’re unsure which direction to take, I’m always happy to offer advice tailored to your home, location, and budget. Every roof is unique, but making an informed choice now will save you considerable trouble in the future.
