How Long Does A Modified Bitumen Roof Last?

A modified bitumen roof is commonly used on commercial buildings. It is durable, flexible, and weather resistant. But how long does a modified bitumen roof last? The answer depends on factors such as your building, industry, and location. Additionally, knowing the expected durability of your roofing material is essential.

So, to help you out, we’re here with a detailed guide that will help give you an understanding of how long a bitumen roof may last on your property. At Better Construction Roofing, we prioritize educating property owners about the roofing industry so they can make more informed and cost-effective decisions.

In this article, you’ll learn the following:

  • The average lifespan of modified bitumen roofs
  • Factors affecting its lifespan
  • Tips to extend its lifespan
  • Whether a modified bitumen roof is the right choice for your property

Average Lifespan Of A Modified Bitumen Roof

Modified bitumen/asphalt roofs are a great investment for many types of properties and structures, be it a small porch on your house, or a big storage facility. They are good at resisting cold weather and saving energy, and on average modified bitumen roofs last between 15 to 25 years when they’re installed and maintained properly. The lifespan varies depending on various factors, including the property’s location, level of foot traffic, and material quality, among others.

To find out how long it will last on your building, it’s essential to understand how all these factors affect the roofing system.

Here’s a detailed explanation of how each factor affects the longevity of a modified bitumen roof:

Factors Affecting A Modified Bitumen Roof’s Lifespan & How You Can Enhance It

From the type of membrane to the installation technique, there are so many things to consider in order to get the best out of your modified bitumen roof. A reliable and experienced commercial roofing contractor will take care of it all. But if you want to ensure your roof lasts as long as it should, you must know what affects its durability.

Local Climate: Choose The Right Modification

There are two main types of modified bitumen roofing: APP (Atactic Polypropylene) and SBS (Styrene-Butadiene-Styrene). APP modified bitumen roofs are typically more heat-resistant, making them ideal for areas with high temperatures and extensive sun exposure. On the other hand, SBS modified bitumen is more flexible and better suited for hail-prone or cold areas with freeze-thaw cycles. You should select the type best for your area’s climate and weather conditions. This will keep your roof in its best condition!

Material Quality: Select A Reliable Manufacturer

The quality of the roofing material chosen greatly impacts the longevity of any roof. So, for a modified bitumen roof, you should choose a good-quality version from a reliable manufacturer, such as CertainTeed, GAF, or Firestone. These industry leaders also offer impressive warranties on their products to cover any damage caused by a manufacturing error.

Foot Traffic: Limit Wear and Tear

Foot traffic is one of the major causes of early wear and tear on a modified bitumen roof, which shortens its lifespan. So, it’s important to limit foot traffic and provide walkways or designated areas for maintenance and repairs. This can help you prevent roof damage and enhance your modified bitumen roof’s lifespan.

Installation Method: A Crucial Decision

The process of installation includes many crucial steps that must be done correctly to ensure the roof is sturdy and durable. First, it’s important to work with a professional roofing contractor who has good experience with modified bitumen roofs. They will use the correct installation methods and techniques as required.

Some of these techniques include:

  • Torch down or hot welding
  • Binding with cold adhesives
  • Using self-sealing membranes
  • Spreading hot asphalt

A proper installation method should be chosen according to the type of membrane and weather conditions in your area. Only an expert roofing contractor can ensure that the installation is perfect, which is also a big deciding factor in how long a modified bitumen roof lasts.

Maintenance: Roof Inspections, Cleaning & Repairs

Regular maintenance is critical to keep a modified bitumen roof in good condition and extend its lifespan. This involves having a good maintenance plan for your roof in place, which generally includes a complete roof inspection every six months, and regular cleaning.


During an inspection, a contractor will check for any signs of damage, such as cracks, blisters, or puncture marks, and make any necessary repairs before the issue gets bigger and causes more damage to the roof.


Dirt, debris, and algae can accumulate on the surface of a roof, which causes damage over time. You can hire a professional contractor to clean the roof using specialized equipment and cleaning solutions to remove any buildup.


Along with inspections and cleaning, it’s important to make necessary repairs promptly. Otherwise, the roof may fail before the end of its lifespan and lead to more expensive repairs or a replacement. It’s not just modified bitumen; every type of roof needs proper care and upkeep to function sufficiently for decades.

Modified bitumen roofs are relatively easy to install, resistant to extreme weather conditions, and help reduce the cost of energy bills. The average lifespan of a modified bitumen roof is slightly higher than other flat roofs such as TPO and EPDM, but it provides a great solution for property owners who are looking for a reliable, long-lasting roofing material.

We hope this guide answered your question about how long a modified bitumen roof will last. If you have any doubts or want to discuss your roofing needs with the experts, feel free to give our company a call.

We Can Solve All Your Roofing Problems!

Whether you have a damaged roof or you need a new one, we’ve got you covered! At Better Construction Roofing, we’ve been repairing and installing high-quality flat roofs for years. We work with some of the top manufacturers, and our staff is highly trained and skilled to handle any roofing material, including modified bitumen variations.

Better Construction Roofing was launched with one aim: to solve all roofing problems in an affordable way, while using top-quality tools and techniques. We’re dedicated to helping our community by offering free consultations, roof inspections, and estimates to all property owners throughout Denver. If you need more information on modified bitumen roofs or want to select a better roofing material for your building, call us at (720) 776-9475. Our commercial roofing experts will answer your questions and suggest the best course of action.

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