March 17, 2025

Modified Bitumen vs. TPO Roofing

TPO and modified bitumen are used for modern flat roofs. These are materials that provide tightness, resistance of the structure to difficult climatic conditions. Each coating has peculiarities of operation, advantages, disadvantages - about what we will tell in the article.

What is TPO roofing: why it is so popular

Thermoplastic polyolefin (TPO) is a relatively young material that became popular for flat roofs in the 1990s.

The predecessor to this coating was modified bitumen, which has been used since the 1970s.

The improved bitumen system was developed as a sealed, durable alternative to traditional asphalt roofing.

The popularity of modern polyolefin is easy to explain:

Suitable for extreme weather conditions, including the Cape Cod climate.
Can withstand drastic temperature changes, extreme heat, and cold.
Maintains flexibility in sub-zero temperatures, which helps to cope with the weight of snow and ice, the impact of hail.
It is easy to maintain, as it is a membrane. This feature allows to reduce operating costs.

TPO – membrane roll building material. In the basis is used polymer – polyolefin. But plasticizers are not included in the composition of this coating, which guarantees the resistance of the membrane to cracking.

Modifiable bitumen is applied to the base with the help of cold glue, hot asphalt mixture, burners. But with polyolefin material, everything is different. Such a coating is attached to the surface mechanically or fixed with a special adhesive composition.

Another bonus of TPO is a layer of glass fiber reinforcement. In addition, manufacturers produce materials with an additional substrate of fiberglass fleece on the back side – to increase strength and the possibility of application in complex projects to reconstruct roofing systems.

Scope of application of thermoplastic polyolefin – commercial buildings (office, retail, industrial, warehouse).

It is possible to use the building material in the creation of roofs for private homes, terraces, green roofs: on top of it you can lay parquet or shiplap, rolled lawn.

Features of modified bitumen roofs

The material is based on the asphalt mixture of the BUR system with the addition of polymer, which increased the flexibility of bitumen, extending its service life.

The coating has a layer of rubber and reinforced glass fiber, which enhances the strength of the material.

Manufacturers produce two types of improved bitumen:

SBS – rubber-like polymer, which is installed using hot cleaned asphalt or cold glue.
APP – plastic-like polymer, which will require a torch for installation.

The building material usually comes in 3-foot-wide rolls, the optimal size that is easy to work with on roofs of any size. The face of the bitumen is UV protected.

Sheets of material are joined together as tightly as possible to provide waterproofing. After laying, another protective layer is added.

Modified bitumen systems can not withstand a large accumulation of water. But there is a solution to the problem:

correct the slope of the roofing surface;
reinforce the waterproofing for proper water distribution.

Therefore, it is necessary to regularly check the condition of coatings, structures, timely eliminate deficiencies, clean the gutters to ensure effective drainage of rainfall, melt water, snow.

Pros and cons of modified bitumen system

Advantages of roofing:

Resistance to temperature fluctuations, heat, cold.
High strength, wear resistance: the material is resistant to deformation, tearing, various mechanical damages.
Operation period – 15-20 years.
Universality of application: bitumen is suitable for buildings of different types and any roofing systems.
Relative ease of installation, repair, maintenance.
Environmental friendliness: the material can be recycled at the end of its service life.

Another advantage – the front surface reflects light due to the addition of special granules. This prevents strong heating of the surface on a hot summer day.

The modifiable bitumen is suitable for the climatic conditions of Cape Cod. This building material can often be seen on the flat roofs of commercial, private buildings in American cities.

There are disadvantages as well:

It is difficult to see where a crack has appeared, through which water is leaking.
With time, the material loses flexibility, begins to crack.
Cannot be laid in wet, rainy weather.
Despite the strength, there is a risk of puncture by sharp objects.

Of the minuses it is worth noting the complexity of installation of some types of bitumen systems – for laying requires strong heating of the surface. For this purpose, special burners are used, which is associated with the risk of burns. Work with this equipment can only experienced roofers who have a license, qualifications, protective clothing and comply with all safety requirements.

In addition, bitumen does not have as many design options as other roofing building materials.

Pros and cons of TPO

Advantages of thermoplastic polyolefin:

Easy installation compared to other roofing materials. Can be laid on top of existing roofing systems.
According to the requirements of operation TPO-roofing will last 20-30 years.
Good adaptation to different weather conditions.
Preservation of flexibility even in frost.
Excellent resistance to ultraviolet radiation. Membrane films white reflect 87% of UV rays, which prevents heating of the roofing system, reduces the cost of cooling rooms.
Resistance to contaminants.
Some TPO membranes are Energy Star rated and approved by the Cool Roof Rating Council.

The choice of polyolefin shades is also pleasing. Manufacturers produce coatings in black, brown, beige, dark gray, light gray, and white. For cold regions, it is recommended to cover the roof with a darker material, so that in winter the roofing surface absorbs more heat, which would reduce energy costs for heating.

TPO is available in custom colors that can be used to match the architectural features of a building or to create a unique visual effect. Manufacturers provide a color retention guarantee. This means that during the lifetime of the polyolefin will not fade.

The minuses of this material also have:

The membrane is unstable to punctures due to the lack of a hard layer that would protect the surface from the fall of heavy, sharp objects, heavy traffic.
TPO can shrink over time if the surface is not properly maintained.
The coating is not resistant to all chemicals, some of them destroy the material, lead to deformation, loss of tightness.

Problems with the membrane roof also arise due to unprofessional installation. For example, if the roofer poorly welded the seams, there will be gaps, and therefore violate the sealing of the coating.

Comparison of modified bitumen and TPO roofing: which suits you best

Both roofing systems are excellent choices for any commercial property or residential flat roof. That said, the materials are suitable for Cape Cod’s climate conditions. So, which to choose as a result? Let’s do a comparison.

Main nuances when choosing a modified bitumen roofing system

If properly installed, the coating of improved bitumen will be airtight. But with a large accumulation of water, the surface will begin to heat up more strongly, will lose adhesion (adhesion with the substrate). The result – leaks, major repairs to the roofing system and interior rooms due to moisture. To prevent this from happening, you need to take care of an effective drainage system, strengthen the waterproofing, change the slope of the roof (if possible).

Modifiable bitumen is used in construction for more than 50 years. Its operational reliability is undeniable. Although some believe that this option is becoming obsolete, new technologies are replacing it. But bitumen roofing is still being installed on buildings throughout the states, including regions with cold and hot climates.

Another important aspect. Bitumen is a recyclable material. It can be reapplied after use. Manufacturers are trying to make the coating more environmentally friendly. But in the manufacture of the coating in most cases, oil and other chemical components are used, which do not belong to the “green” raw materials.

During installation, difficulties may arise. Laying will require special adhesive compositions, asphalt mixtures, powerful burners to heat the surface and bond it to the base. All this requires competence from roofers, increases the cost of the work.

It should also be taken into account that in most cases the average warranty is 10-12 years.

Nuances when choosing TPO roofing

It’s cheaper. TPO has already managed to prove itself on the positive side. If you compare the prices of modified bitumen and thermoplastic polyolefin, the cost of the latter is lower. Installation, maintenance will also cost less. Laying the membrane is much easier, since you do not have to deal with asphalt compositions, heating burners.

Greater durability. Unlike bitumen systems, polyolefin systems can withstand large volumes of water. This means that you do not have to change the slope of the roof or install additional drainage structures. In addition, TPO – a very elastic material, resistant to the appearance of cracks.

Many colors. If you do not want a boring gray or black roof, then thermoplastic membrane – one of the options. You can pick up beige or white polyolefin. Or find an unusual shade, which can be found among the proposals of manufacturers.

Durability. The average service life of this building material is 15-20 years. Some companies provide a warranty for 30 years.

Do not forget about the rules of safety, operation, maintenance of flat roofs from bituminous and polyolefin materials:

Planned inspection – once a year. Also, surface diagnostics is carried out after heavy rains, snowfalls, hurricanes. For example, Roofing & Siding of Cape Cod specialists use drones, infrared emitters to assess the condition of the structure.
Snow removal if the snow load exceeds the design load. Wooden or plastic shovels, long-bristled brushes are suitable for clearing.
Cleaning gutters, gutter system funnels from leaves, branches, debris. It is necessary to make sure that in winter ice plugs do not form.
Never leave foreign objects on the roof: ladders, sharp tools, equipment – anything that can violate the integrity of the roll material.
To go on the roof, repair work, maintenance is carried out only under the supervision of qualified roofers or management company.
The inspection draws attention to any damage to the waterproofing. The problem is eliminated with special polyurethane sealants or mastics. The work is carried out by experienced roofers who provide a guarantee for the services performed.

Also prohibited is the unauthorized installation of technological equipment: antennas, transmitters and other units. Such work should only be carried out by employees of licensed management companies.

Choosing the right roof

The experts at Roofing & Siding of Cape Cod can help you choose the right roofing material for a strong, tight, durable roof. We take into account the area, architectural features of the object, climatic conditions of Cape Cod and the client’s preferences during the selection.

Why turn to our company:

Experience – over 10 years.
Providing expert advice on installation, repair, maintenance of roofing systems.
Complex solutions for private and commercial facilities: shopping centers, stores, offices, warehouses, industrial buildings.
The use of modern tools, equipment.
Ecological building materials.
Compliance with technology, quality standards, safety.
Precision, attention to detail.

Each roof in Roofing & Siding of Cape Cod – a tight, energy-efficient design, resistant to heavy rain, snowfall, UV radiation, wind loads, mechanical damage. The client receives a roof with excellent insulation, which allows you to save significantly on heating the house.

Get a free estimate by filling out the online form on the website or calling (508) 938-8410. We will provide you with a detailed consultation during normal business hours.

We work in Cape Cod even with complex projects. From the roof to the facade, we can help you realize your home makeover ideas.

Dmitry Labkovich

Since 2002, I have dedicated my career to construction, starting as a cleanup worker and laborer. Despite tough conditions, I quickly mastered roofing and siding, and within six months, I was handling complex tasks. Later, I became a subcontractor, growing the business with a partner and expanding our team.

In 2011, I founded Roofing and Siding of Cape Cod and Boston. At the same time, I continued working with major firms, building a reputation through high-quality work and excellent service. In 2010, I joined the Coast Guard Reserve, which helped me develop leadership skills. Before my deployment in 2018, I built a reliable team that ensured steady company growth.

Today, Roofing and Siding of Cape Cod and Boston is a team of 30+ professionals, all OSHA-certified. We continue to expand while maintaining top-quality standards and exceptional customer service.

**Experience & Expertise**

- 20+ years in the roofing and siding industry
- Hands-on experience from laborer to business owner
- Managing a team of 30+ professionals
- Business development and client relations

**Education & Certification**

- Practical training in roofing and siding techniques
- OSHA safety certification
- Coast Guard Reserve service experience
- Ongoing professional development in construction