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4 Most Common Commercial Roofing Materials

If you are in need of excellent roofing materials for your commercial building, rest assured that this article provides answers to your questions. Having to choose the best among the numerous commercial materials in the market seems overwhelming.

Based on my experience, I can feel how challenging it is to know which roofing material is the best for your specific building. The following are the 4 most common types of commercial roofing materials:

  1. Modified Bitumen
  2. Build Up Roofs
  3. Metal Roofs
  4. Spray Foam Roofs

Years back, I was in your shoes looking for the best roofing material for my new apartment. I had to go through a series of articles to finally make a choice of the best roofing material that would befit my apartment.

I will base this article on my personal experience and experiences gathered from various building contractors.

With this article, I will be showing you the most common roofing materials in the market and the benefits offered by each. Among the factors that I will be talking about is lifespan, ease of installation, fire resistance, and many others.

Sit tight and let me take you on a ride. 

1. Modified Bitumen

Modified bitumen, also known as “modified asphalt” or “mod bit” roofing materials is sold in rolls and is suitable for low slope or flat roofs. Its seams are sealed with a torch so as to heat the underside of the bituminous material.

Methods Of Installation

You can install modified bitumen roofs using one of the various methods, such as cold applied, heat weldable (torched seams), hot-applied and self-adhered.

Though I consider this material quite durable, the manufacturer label has its life span as just 10 years.

You might be concerned about the meaning of the attached “modified”? 

According to ARMA (The Asphalt Roofing Manufacturers’ Association), you will read that generally, modified bitumen utilizes asphalt — a traditional waterproofing medium — modified with atactic polypropylene, styrene-butadiene-styrene, synthetic rubber or other agents capable of creating a uniform matrix which improves the physical properties of the asphalt. 

The best bitumen modifiers are the atactic polypropylene and the styrene-butadiene-styrene.

Identifying A Modified Bitumen Roofing

How can you identify a roofing material to know it is modified bitumen roofing material? Below are what you need to watch out for:

If you examine the edges of the material, modified bitumen is thicker with a sealed edge done by heating with a torch. If it is heated using a torch, you should see a runout of melted bitumen. If there is no sign of runout bitumen, then it means it was heated insufficiently or heated using another mean. If it wasn’t sufficiently heated, its durability is lessened. 

Secondly, measure the width between its seams parallel and roof eaves. Modified bitumen is normally 39″ wide with an overlap of an inch or two. 

Thirdly, modified bitumen is not only thicker but better at resisting tearing and breaking. If you try to tear it and you discover it easily gives itself out, it is probably not a mod bit.


  • High Durability
  • Excellent performance in extremely cold weather.


  • Fire Hazardous

2. Built-Up Roof

Built-up roofing is the most popularly used roofing materials suitable for low-slope roofs. Due to its ability to create a continuous sealed surface, I would recommend it for low slope or flat roofs. 

Types Of Built-up Roofing

Built-up materials are not new. They have been in existence for more than 100 years.

The built-up roofing ply sheet is special fabrics reinforced with fiberglass or organic materials. Each of the ply sheets is laid over cold or hot bitumen to firmly bind it to the roof. Commonly, ply sheets are manufactured with a standard width of about 36 inches.


Depending on the materials used and the climate, built-up roofing has a lifespan of 15 to 30 years. With this life expectancy of build-up, it stands side by side with composition (asphalt) shingles of a 15 to 30 years lifespan. 

The balanced roofing is a special type of built-up roofing that uses large stones for its surface layer. In this case, the lower layers are not fastened to the roof, and the heavy surface layer holds the roof.


  • Excellent waterproofing and ultra-violet protection.
  • Fire-resistant.
  • Low cost of maintenance


  • Potential hazardous fumes
  • Prone to water damage
  • High cost of installation

3. Metal Roof

A metal roofing is a roofing material that is made from metal pieces or tiles distinguished by its high resistance, impermeability and long lifespan. This roofing material is produced from various materials. These materials including steel, aluminium, stainless steel, copper, and zinc alloys. Each of these materials has effects on durability, price, appearance, and more.

 The most commonly available metal roofing materials are steel and aluminum. This is because they are fairly economical, durable, and hold paint finishes well.

Expected Lifespan

If properly installed, a metal roof should last as long as the house, surviving high winds, sealing out water, and easily shedding snow. Metal is resistant to fire, rot, mildew, and insects.

Although warranties widely vary, most companies label their products with 20 to 50 years. Paint finishes typically have a limited warranty of 30-year.


A metal roof must be properly installed. Roofs with exposed fasteners are extremely prone to improper installation. If screws are attached through the flat surfaces (instead of the raised ridges), rainwater can find its way down the roof and seep into the screw holes. Due to this, special resilient washes must seal around screw heads. 

Also, if you are installing this type of roof, endeavour to precisely follow the manufacturer’s instructions.


In comparison with the weight of tiles with 750 pounds per square, or concrete tile having a weight of 900 pounds per square, metal roofing is extremely lightweight. 

If you would wish, you can downsize the number of roof support members of your ongoing building.

Most metal roofing materials have multiple-shingle sections or 12- to 36-inch-wide panels. This is fast to install for an accomplished contractor. In case your roof strips off or there is a feasibility for a storm, the process can be shortened by a day or two. This also reduces the cost of labour.

This is also fire resistant. Owing to the fact that metal roof materials are noncombustible, they are rated high in the aspect of being resistant to fire.


One thing you might not find attractive with this material is the initial cost. This is still not a deal-breaker because if you apart from the initial cost, you are relieved of the save on seasonal maintenance. 


Another aspect you would like about these materials is the minimised noise. Some people enjoy the knocking sound of the rain while others find it uncomfortable. This material makes sure that this noise is brought to the minima. 


  • Reduced heat condition
  • Fire resistant
  • Easy of installation
  • Minimum noise


  • The high cost of installation

4. Spray-On Roofing (Foam)

Spray Polyurethane Foam, shortened as SPF, is a material that starts as a liquid spray, instantly transforms into a foam, and gradually hardens to form a solid layer. This particular low-cost roofing material is applied on top of an existing roof. Although not well-known, the spray-on roofing material has been around as far back as the early 1960s.


An SPF roofing system is waterproofed and serves as an insulating factor. It is suitable in any climate and has a lifespan of about 50 years with proper installation and maintenance. 

Suitable Climate Of Installation

You can install spray-on roofing material only when the weather is favourable. You can’t install it when there is snow, ice or water. And once you are through with the installation, you are to come back every six months to inspect the roof. 


  • Waterproof
  • Insulating factor
  • Good for all climates 


  • Selective installation weather

In conclusion, if your commercial building needs a new roof and you are considering the best roofing to go for, choose any of the above roofing materials. In making your choice, have the following factors in mind.

Is your room walked-on, visible, endangered by grease, chemicals, or acid, facing the direction of the sun, endangered by high wind, or temperature extremes? Your choice should be influenced by several climates and several types of building usage. 

Also, have in mind longevity and the maintenance cost. The color and energy cost of each building material should be considered as well. A cold-weather climate office will need a dark-colored roof to reduce its heat, while a warm climate building will appreciate a white roof to limit the burden on its air conditioner.

Contact Behmer Roofing

Behmer is ready to take on your toughest roofing challenges. Located across Arizona, Behmer Roofing handles all projects from roof replacements, maintenance, new construction and commercial roofing. Contact us today for more information.