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How Long Does A Built-Up Roof Last? 

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How Long Does A Built-Up Roof Last? 

Are you looking for ways to take your commercial flat roof to the next level?

If you are also searching for popular commercial roofing materials then a built-up roof will surely make the list. 

In our last blog post, we extensively covered what a modified bitumen and built-up roof were. But as you get closer to making a decision on which roofing material you want to use, you surely will want to know about the life expectancy of your intended material. 

Today we will deep dive into the question: How long does a built-up roof last? We will also discuss factors that can affect its lifespan, and how you can also improve it. 

What’s A Built-Up Roof? 

A built-up roofing system, commonly known as a BUR system, is a type of flat roofing material used mainly on commercial buildings and some residential flat roofs as well. 

As the word suggests, this system is built up with several layers of material. 

This roofing system is constructed by layering multiple layers of asphalt and reinforcing fabrics to create a waterproof and weather-resistant barrier. The layers are applied in alternating fashion, with each layer being hot-mopped or cold-applied using adhesives or bitumen. The result is a thick and sturdy roof that can withstand the elements and provide long-lasting performance.

Built-Up Roof
Built-Up Roof

The Average Lifespan Of A Built-Up Roof

Let’s now move on to the main question of this article. A well-constructed built-up roof can last anywhere from 20 to 30 years, and in some cases, even longer with proper maintenance and regular inspections. However, factors such as harsh weather conditions, lack of maintenance, and other external factors can significantly affect the lifespan of a built-up roof negatively. We will cover all of this in the section below. 

Factors Affecting The Lifespan Of A Built-Up Roof

A built-up roof, also known as a BUR, is a popular choice for commercial buildings due to its durability and longevity. But just how long can you expect a built-up roof to last? Well, the answer depends on several factors

Quality Of Installation

One of the most important factors that can affect the lifespan of a built-up roof is the quality of the installation. There are several methods of installation for a built-up roof, such as hot application (which deals with heating the asphalt on site), cold application, or ballasted. All of these methods require a high level of expertise and experience. 

If the roof is not installed properly, it can develop leaks and other issues that can significantly reduce its lifespan. This makes it essential to hire a qualified and experienced roofing contractor who has expertise in installing built-up roofs. They will ensure that the layers are properly applied and that all the seams are sealed correctly to prevent water penetration.


Tampa has a lot of quality roofing contractors. In our blog post about the best roofing companies in Tampa, we shared a list of some of the best names in the roofing industry who serve Florida. 

Quality Of Materials Used In A Built-Up Roof 

Another factor that can impact the lifespan of a built-up roof is the quality of materials the contractor uses for installation. It is crucial to use high-quality materials that can withstand the harsh weather conditions and provide long-lasting durability. 

Inferior materials may deteriorate quickly and result in premature failure of the roof. Even if the roof is installed perfectly, without any issues, low-quality materials can impact it. Investing in top-grade asphalt, gravel, and other components will ensure that the built-up roof withstands the test of time.


Climate conditions also play a role in the overall lifespan of the roof. Extreme weather conditions like heavy rain, strong winds, and intense heat are all common in Florida. They can put a lot of strain on the roof. Over time, these weather events can cause damage to the layers of the built-up roof, leading to leaks and other issues. 

So, if you live in an area with harsh weather you should take extra precautions to ensure that your built-up roof is properly maintained and repaired as needed.

Proper Insulation And Ventilation

While having proper levels of insulation and ventilation is crucial for residential, pitched roofs, it’s also essential for tar and gravel flat roofs as well. 

Adequate ventilation helps regulate temperature and moisture levels in the attic space, preventing excessive heat buildup and moisture retention that can damage the roof. Without proper ventilation, trapped heat and moisture can cause the layers of the built-up roof to deteriorate more quickly.

Lifespan Comparison With Other Materials 

Up until now, we’ve only covered how long a built-up roof lasts and the reasons behind it. As a standalone, the lifespan of 20-30 years is impressive, but what about when we compare it with other common types of commercial roofing? Let’s find out!


TPO is a new but exciting commercial roofing material. This is a white-colored single-ply roofing membrane that is heat welded on your flat roof. Like a built-up roof, a TPO roof has a lifespan of 20-30 years. 

How Long Does A Built-Up Roof Last?  How Long Does A Built-Up Roof Last
TPO Roofing

Modified Bitumen

Mod bit roofs may not be as popular as they originally were, but they are nevertheless still used on commercial properties.

You can expect a mod-bit roof to last for 15-20 years. 

Modified Bitumen
Modified Bitumen


Lastly, we have EPDM, which stands for ethylene propylene diene monomer. EPDM roofs are made up of a synthetic rubber material that is highly durable and resistant to UV rays and weathering. EPDM roofs have a lifespan of around 20 to 25 years with proper maintenance.


Final Thoughts

Understanding the lifespan of a built-up roof is crucial for homeowners and property managers alike. As we have discussed in this blog post, a well-maintained built-up roof can last anywhere from 20 to 30 years, and to ensure that the roof lasts for maximum time it is essential that you take care of it through the following: 

  • Regular roof inspections
  • Cleaning of the roof
  • Minimal foot traffic

So, if you have a built-up roof or are considering installing one, make sure to invest in routine maintenance and timely repairs to ensure its durability and maximize its lifespan. 

When it comes to repairs and maintenance, there is no one else in Tampa like the team at SouthShore Roofing & Exteriors. Call us today, at (813) 400-3329, to install your new flat roof. We’ve been serving homes and businesses in Tampa for years and want to help you!

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