If you own or manage a building with a flat roof, you may wonder, how long do flat roofs last?
This article will look at the lifespan of flat roofs, warranty periods, and the role of maintenance.
How Long Do Flat Roofs Last?
The lifespan of a flat roof can vary greatly, but generally, they last between 15-30 years on average before needing replacement.
More durable materials like EPDM rubber can last 50 years or longer.
Regular maintenance and inspections are key to maximizing the life of a flat roof.
Key Points
– Flat roof lifespans range from 10-50+ years depending on the material
– EPDM rubber, thermoplastic, and PVC roofs last the longest
– Regular inspections and maintenance are critical
Our Opinion
In my experience as a roofing contractor, a high-quality flat roof installed properly can easily last 25-30 years with proper care.
I typically recommend thermoplastic or EPDM rubber for long life expectancy.
With regular maintenance like clearing debris and repairs as needed, a flat roof can last just as long as a pitched roof.
Proper installation is key, so be sure to hire an experienced flat roofing contractor.
What Is the Typical Lifespan of a Flat Roof?
The lifespan of a flat roof can vary greatly depending on the type of roofing material used. Modern flat roofs made with plastic, rubber, or membrane materials typically last 20-30 years. More traditional materials like felt may only last 10-15 years.
Here are some typical lifespans for common flat roofing materials:
- EPDM rubber – Over 50 years
- TPO or PVC membranes – Up to 30 years
- GRP fibreglass – Around 25 years
- Asphalt or bitumen – 20-25 years
- Felt – 10-15 years
The skill of the installer is also important. An experienced roofer can get over 25 years from a high-quality flat roof system if installed correctly. Choosing a reputable company is key to maximising the lifespan of a flat roof.
Overall, materials like rubber and plastic have extended the typical lifespan of a flat roof to 25-30 years. With regular maintenance and high-quality materials, a flat roof can even last 50 years or more.
Factors Affecting How Long Flat Roofs Last
Several key factors determine the lifespan of a flat roof:
- Roofing material – More durable materials like EPDM rubber or TPO membranes last longer than felt or asphalt.
- Installation quality – Proper installation by an experienced roofer ensures the roof’s longevity.
- Climate and weather – Hotter climates and severe weather events can degrade roofs faster.
- Roof slope – Flatter roofs allow water to pool, while steeper slopes improve drainage.
- Regular maintenance – Inspecting and repairing a roof annually helps prevent leaks and damage.
- Roof traffic – Heavy foot traffic accelerates wear and tear.
- Underlying structure – A compromised roof deck will undermine the surface materials.
Choosing a high-quality roofing system and hiring a reputable installer are the best ways to maximise lifespan. Preventative maintenance, minimising foot traffic, and repairing problems quickly also keep a flat roof performing longer.
With good materials, proper installation, and regular upkeep, it’s possible to get 50 years or more from a flat roof.
Differences in Material Lifespans
The expected lifespan of a flat roof varies significantly depending on the roofing material used. Some materials are inherently more durable and weather-resistant than others.
At the lower end, built-up roofing felt lasts 10-15 years on average. Asphalt coatings may extend this lifespan slightly, but overall felt roofs require frequent repairs and replacement.
Modified bitumen can last 12-20 years with proper installation. The modified composition makes it more flexible and durable than standard asphalt.
Single-ply PVC and TPO membranes offer a 20–30-year lifespan. Their seamless, single-sheet construction resists leaks and tears.
EPDM rubber roofs are highly durable, lasting 25-30+ years with proper maintenance. The rubber’s flexibility handles expansion and contraction well.
Finally, spray polyurethane foam roofs offer the longest lifespan at 30-50 years. The seamless foam forms a protective barrier over the roof.
Overall, synthetic single-ply and spray-on systems outlive built-up and modified systems. However proper installation and maintenance are vital to maximise any roofing material’s longevity.
The Role of Maintenance
Regular maintenance is crucial for any flat roof to achieve its full lifespan potential. Even the most durable materials require proactive care and attention.
The main maintenance tasks involve clearing debris, checking for leaks, inspecting flashings, and repairing cracks or damage. Gutters and drains must be kept clear to prevent water pooling.
Roof coatings also need to be reapplied every 5-10 years to renew weatherproofing and UV protection. Catching and repairing minor damage early prevents bigger issues down the line.
For built-up roofs, gravel may need raking and loose aggregate re-spread. Single-ply membranes should be checked for tears, punctures or lifted seams.
Overall, a little preventative maintenance goes a long way. It’s recommended to inspect flat roofs twice a year and after major storms. An ounce of prevention avoids expensive repairs or early replacement.
With proper installation and proactive care, quality flat roofing can serve you well for decades. However, neglecting maintenance is asking for trouble regardless of the material used.
Flat Roof Warranty Periods
When considering how long a flat roof will last, the manufacturer’s warranty period gives a useful baseline indication.
However, warranties alone don’t guarantee longevity. Proper installation and ongoing maintenance are equally important.
For built-up roofs, warranties typically cover 10-20 years. Modified bitumen warranties range from 10-30 years depending on the material thickness.
EPDM rubber roofs often come with 10-15-year warranties, while TPO and PVC membranes usually offer 15-20 years of coverage. Some premium TPO products now offer 25-30-year warranties.
Metal roofing warranties can extend up to 50 years for high-quality steel and aluminium. Concrete roof tiles also often come with 50-year warranties.
In general, the more layers and coatings a flat roof system requires, the shorter the warranty period. The most vulnerable components are the seams between sheets.
Warranties give useful guidance, but real-world longevity depends on proper installation, climate, roof use, and maintenance. With care, many flat roofs last well beyond the warranty period.
FAQ
How often should a flat roof be replaced?
Flat roofs should be replaced every 15-30 years depending on the material. Asphalt and roll roofing may need replacement every 10-15 years. EPDM rubber and thermoplastic roofs can last over 30 years before needing replacement.
What is the life expectancy of a flat roof?
The average life expectancy of a flat roof is 15-25 years. More durable materials like EPDM rubber can last over 50 years. Asphalt, roll roofing and built-up roofs tend to last 10-20 years.
How often should a flat roof be checked?
A flat roof should be inspected at least twice a year, in spring and fall. Look for signs of damage, leaks, pooling water, and debris. Annual professional inspections are recommended as well.
Should I avoid a house with a flat roof?
Not necessarily. With proper installation and maintenance, a flat roof can last as long as a pitched roof. Make sure to inspect the roof and have a professional assess its condition before purchasing a home with a flat roof.
Conclusion
In summary, how long flat roofs last depends on the roofing material used and proper maintenance. While some only last 10-15 years, materials like EPDM rubber can last over 50 years. Regular inspections, repairs and following best practices for flat roof installation and care are key to maximizing the lifespan of a flat roof. Proper maintenance is essential to get the most out of any flat roof.
