How Long Does A Metal Roof Last?

Whether you’re building a new home, or renovating an old one, metal is one of the most durable roofing materials around. But just how long does a metal roof last?

In this guide we cover everything you need to know about how long different metal roofs last and share our top tips for how you can prolong the lifespan of your metal roof.

Types of metal roofs

When most people think of a metal roof, the traditional Aussie corrugated tin roof springs to mind. While they’re still a popular option, there’s a much wider range of metal roofs available now.

The most common metals used for roofing include:

• Steel – an alloy composed of iron and carbon. This combination of carbon and iron is what makes steel one of the strongest and most durable building materials available. When people refer to ‘tin’ roofs these days, they’re usually referring to steel.
• Aluminium – a lightweight but strong metal that’s naturally rust resistant making it ideal for use in coastal areas.
• Copper – loved for its bright pink-orange sheen that develops a gorgeous green-blue patina over time, copper’s one of the oldest roofing materials around.
• Zinc – an elegant grey metal that makes a long-lasting, low-maintenance roofing option.

For an in-depth guide to the pros and cons of each of these metal roofs, check out this guide to Types of Metal Roofs & How to Choose Them.

How long does each type of metal roof last?

Generally speaking, you can expect a properly maintained metal roof to last upwards of 50 years. You only have to look at the copper roofs of old European cities to know metal is a durable material.

While you get a similar lifespan out of slate and clay tiles, you’ll typically only get thirty or so years out of asphalt or concrete tiles.

But exactly how long you’ll get out of your metal roof will depend on the metal you choose.

Steel roof

Expect to see at least 50 years of life out of a properly installed, well-maintained steel roof. Unlike other metals, steel is an alloy, which means it’s comprised of two other compounds – carbon and iron. Because iron is prone to rusting, modern steel roof sheets are usually coated with a corrosion-resistant layer to increase their lifespan. If you like steel but want to reduce the risk of rust further, opt for stainless steel sheets, which include chromium to prevent corrosion. They’ll be a bit more expensive but you might get an extra ten years out of them.

Aluminium roof

Aluminium roofs generally have a lifespan of between 50 and 70 years. Aluminium isn’t prone to rusting, because it doesn’t include any iron. However, it’s lighter weight and slightly less dent-resistant than steel.

An aluminium roof will also expand and contract more with variations in temperature than a steel roof, which means it’s essential to have it installed by a professional.

Copper roof

Naturally rust resistant, copper is one of the most durable roofing metals and can easily last up to 100 years. The key thing to remember however is that the copper will change colour over time as it develops a patina. So while your roof might last 100 years, it won’t stay the same colour over that period.

Zinc roof

Like copper, zinc is a premium building material that will last in excess of 100 years if properly installed and maintained. It corrodes at a very slow rate, and will stand up well to the elements with very little cleaning required.

How long do corrugated metal roofs last?

Because most corrugated metal roofs are made from steel, you can generally expect a corrugated metal roof to last between 40 and 60 years. However, as with any roof, this will depend on the quality of the installation and maintenance.

How much does a metal roof cost?

Metal roofs don’t come cheap. But they also last a lot longer than other building materials, which can make them a more cost-effective option over the long run.

Depending on the type of metal you choose, you can expect to pay between $35 and $200 per square metre for a metal roof. While a basic steel roof will generally be on the cheaper end, copper and zinc will be significantly more expensive.

The biggest factors that influence cost are the size of the roof, the metal you choose, and the type of sheeting you use.

How to clean metal roofing?

Over time, exposure to the elements and chemicals in the air, can cause metal roofs to develop a layer of grime. Depending on the climate, they can also develop mould, lichen or algae which if left on the roof can cause stains which are hard to remove.

Cleaning your metal roof about once a year is the best way to prevent this build-up from becoming thicker and harder to clean off. When it comes to how to clean metal roofing, recommend the following:

• First, sweep off any leaves and remove any dead branches or other debris from the roof. It’s a good idea to do this whenever you’re cleaning out your gutters, which we recommend everyone do twice a year.
• If you’ve only got dirt and dust built up on the roof, you can use a pressure washer or hose to rinse most of it off. We generally recommend avoiding harsh solvents and other cleaning products because if used incorrectly they can strip the metal roof, causing permanent damage. If you find water alone isn’t enough to remove the dirt, try using a soft broom, sponge or mop to wipe particularly stubborn sections—just avoid harsh bristles that can scratch softer roofing metals.
• If you’ve got lichen or mould growing on the roof, water alone is unlikely to remove it. In that case, mix some laundry detergent and bleach with water, and apply it with a damp cloth to the affected areas. With a bit of elbow grease, the lichen and mould should come right off.

To find out more about the benefits of metal roofing, contact Strongguard to chat with one of our friendly roof and gutter experts.