Along with the building’s frame, the roof is one of the most important structural elements of any home. A well-designed roof not only protects your home from the elements but can add aesthetic appeal to your house.
While the vast majority of well-maintained roofs last for several decades, they don’t last forever, and ‘how often do roofs need to be replaced’ is a question we’re often asked.
How often do roofs need to be replaced?
‘How often do roofs need to be replaced’ is a common question among home buyers. Roofs are one of the most expensive aspects of a build and one of the most important to get right. With the right design and regular maintenance, it’s not unheard of for roofs to last 50 years or more before requiring major renovations.
How long before a roof needs to be replaced typically depends on four main factors:
1. The materials used to construct the roof
Alongside the quality of construction, the material your roof is made out of will have the biggest impact on its lifespan. Each roofing material has a different average lifespan—and they can vary quite substantially. For instance, while a copper roof can easily last up to 100 years with proper maintenance, asphalt tiles will typically need to be replaced at around the 30 year mark or earlier. As a rough guide, you can typically expect:
- Metal roofs, including steel, zinc, copper and aluminium roofs to last upwards of 50 years. You only need to look at the copper roofs of centuries’ old European buildings to know metal is highly durable.
Slate tile roofs to last a minimum of 75 years, with many lasting well in excess of 100 years before needing to be replaced. You might need to replace a cracked tile here or there, but slate roofs are one of the best wearing roofs on the market.
- Clay tile roofs to last a minimum of 50 years and often up to 100 years. The clay and terracotta tile roofs found throughout Asia and southern Europe are a great example of how durable this building material is.
- Concrete tile roofs to last a minimum of 30 years and up to around 50 years.
- Asphalt shingle roofs to last 15-30 years.
2. The quality of the original installation
Roofs are designed to last, and when properly installed, a roof shouldn’t need to be replaced until the materials’ reach the end of their natural lifespan. Proper installation is essential for ensuring a roof is structurally sound, watertight and capable of withstanding wind pressure.
3. Whether the roof has been regularly maintained
Regular maintenance is vital for prolonging the lifespan of your roof, as it allows you to fix small issues before they become major problems. While a few cracked roof tiles, or a loose metal sheet, might not seem like a big deal, they can easily create bigger problems down the track by letting water seep into the building.
4. The weather in your region
Roofs are intentionally designed to withstand the elements—but that doesn’t mean the weather doesn’t take its toll. If you live in an area prone to high winds, heavy snowfall, or frequent storms, your roof might need replacing earlier than expected, purely from the wear and tear placed on the roof. Freak storms are also a leading cause of roof replacement, particularly if they come with large hailstones, or topple trees.
How do you know a roof needs to be replaced?
It’s one thing to understand in theory how often roofs are meant to last, but how do you know a roof needs to be replaced? Here are some tell-tale signs to look out for:
1. The roof is more than 30 years old
A good rule of thumb to know how long before a roof needs to be replaced is that if your roof is more than 30 years old, it likely requires some maintenance. While most roofs will last well in excess of 30 years, others won’t. Take asphalt shingles for example, which have a lifespan of 15-30 years. Paying attention to your roof’s age won’t tell you exactly how long before a roof needs to be replaced, but it’s a good barometer for the type of wear and tear you can expect.
2. There are visible signs of damage
Regularly inspecting your roof is really the only way to answer the question of when a roof needs to be replaced. Signs of damage to look out for include:
- Sagging in the roof is a major sign of a structural problem that needs to be addressed right away.
- Leaning or detached gutters may indicate water damage in the fascia board—the board that runs along the lower edge of your roof.
- Chipped, cracked or missing tiles, may allow water to seep into the roof cavity.
- Loose roof flashing, may allow water to penetrate the roof. Flashing is an important component of your roof that helps to deflect water away from roof joins or seams.
- Loose or raised nails on either shingles or corrugated iron panels.
- Rusted spots form over time as moisture creates iron oxide. Most modern metal roofs are galvanised, which means that the base metal is covered in a rust-resistant protective zinc coating. However, older roofs may not be, and the galvanised layer can wear off over time. Because rust can eventually wear through an iron sheet, it’s important to replace the affected patches as soon as you notice them.
3. There is a damp patch in your ceiling, or the ceiling is leaking
If you’ve noticed a damp patch in your ceiling, which may look visibly wet, be a shade darker than the surrounding paint, or leave a visible ‘tide’ mark, it’s worth getting a builder or roofing contractor to come and inspect your home. A damp patch in the ceiling isn’t always caused by a leaking roof, but it can be, and it’s vital to get the problem fixed before the moisture leads to major structural damage. The same is true if water is dripping from the ceiling after major rainfall. The cause isn’t always the roof, but it can signal a problem with the roof’s sealant which needs to be addressed.
4. There was a severe thunderstorm, with large hail, in your region
Roofs are durable, and withstand the vast majority of storms. However, hail damage is a leading cause of roof replacements, particularly if the roof is made from a softer metal like zinc. Always inspect your roof after a major storm to check for signs of damage. While it can be tempting to assume that if the ceiling’s not leaking, everything’s ok, water seepage doesn’t always show up immediately.
Top tips for prolonging the lifespan of your roof
The answer to ‘how often do roofs need to be replaced’ should really be: not that often. There will always be some factors about your roof that you can’t change—particularly if you’ve bought a relatively new house and don’t want to replace the roof just yet. The good news is that there are a few simple steps you can follow to prolong the lifespan of your roof. These include:
- Hire a professional, qualified roofing contractor to install your roof. Always do your research and make sure your tradie’s accredited, and be sure to do some basic research to make sure they deliver work to a high standard. While it can be tempting to DIY everything, particularly if you’re building your own home, roofing is an art and it’s better to let the professionals do their thing. It’s particularly important to hire a professional to install a flat roof, as they can be more prone to leaking than traditional gable roofs, especially if water is allowed to pool on the surface.
- Use quality materials to construct your roof. Whether you’re building a new roof, or replacing an old one, it’s a good idea to consider the full suite of options rather than just going with what you know. While some materials such as zinc or copper may cost more upfront, their longer lifespans can pay dividends in the long run by minimising the cost of maintenance for your roof.
- Inspect your roof on a regular basis for any signs of damage, such as cracked tiles, loose metal sheets or surface mould. You should also inspect the gutters—particularly if you’re approaching bushfire season—as clogged gutters can contribute to water leakage. We recommend a thorough roof inspection at least once per year, to catch any issues before they cause major damage. Always read up on how to do this safely, and use the ladder with care.
- Hire a builder or roofing contractor to inspect the roof for you if you don’t feel comfortable climbing up on a ladder and inspecting the roof yourself.
- Address small problems as soon as possible. Replace cracked or missing tiles, reattach loose guttering, clean mould from the roof. These simple tasks might seem like a hassle at the time, but they’ll save you a bigger headache down the track.