A detailed review of easy Commercial Roof Replacement

Roofs, be it for residential or commercial buildings, have one primary function. This is to protect the building and its constituents (human and items) from the elements. Commercial roofs, however, are slightly different from residential roofs due to their size, steepness, and the type of materials used.

Since the commercial roof is an important component of the commercial building, s important to find a quick resolution in the event of any damage. Repair or replacement may be a bone of contention, but it is better to replace if the roof is an old one and it is severely damaged. 

Understanding the primary factors involved in a commercial roof replacement can help in the decision to replace. It also helps decide what type of replacement to choose and how much to budget. Towards this, this article is ca comprehensive overview of the process and requirements of replacing a commercial roof.


  1. Types of Commercial Roofs
  2. Factors to consider in changing Commercial Roofs
  3. Benefits of Commercial Roof Replacement
  4. Conclusion

Types of Commercial Roofs

There are many types of commercial roofs in use today. In this article, we will be focusing on the most prominently used types. The information gained about them can be used to make inferences about other rarer types. 

Metal Roofs

Metal roofs are one of the oldest roofing systems, yet, they are still popular because there are different types. Aluminum, Copper, and Stainless-steel roofs are the most popularly used today for their aesthetics and durability. Metal roofs are recyclable and require little maintenance in their service lives. In replacing your metal roof, you can install new shingles over the existing ones. 

This allows operations to flow smoothly without needing a pause to have the roof fixed. The new roof can be attached to the existing roof surface using acrylic coatings made from polymers that fit firmly to the old roof, making it water-tight. Averagely, the cost of replacing a commercial metal roof is between $8.00 and $15.50 per square foot.

Modified Bitumen Roofs (Mod Bit)

Modified bitumen roofs are made up of asphalt that has been made more flexible by mixing it with rubber. Other materials are also added to it to improve its strength and stability while in service. Bitumen is a material used in asphalt as a binder to hold the sand aggregates together.

Mod bit roofs are durable and can withstand tensile loads more than other commercial roofs. They are easy-maintenance roofs and can be installed quickly. This type of roof is installed as a two or three-ply system using heat to melt the bitumen so that it is liquid and, on cooling, solidifies and hardens. 

Modified bituminous roofs will cost between $9.20 to $13.0 per square foot to replace.

Vegetative Roofs

Vegetative roofs, also known as green roofs, are a very versatile type of commercial roof. They have living plants fitted in on the top surface of the roof. Green roofs effectively control stormwater making them a sustainable option for commercial properties and businesses. 

This water control is the major advantage of these roofs as it protects commercial buildings from the element, ensures drainage, and simultaneously improves energy efficiency.  For vegetative roofs, a seal is critical at the base of the roof system to keep it effectively water-resistant. The average cost of having a vegetative roof replacement is $8.50 to $13.50 per square foot.

Built-up (BUR) Roofs

Built-up roofs, simply referred to as BUR, comprise alternating layers of asphalt and fabrics called roofing felts. These felts are reinforced with glass-fiber mats or other organic mats bonded together with bitumen. They are arranged in layers called plies which imbue the BUR system with sufficient redundancy, meaning if one layer fails, other layers compensate for that layer. 

BUR roofs are very durable and resistant to heavy impacts and stresses that attempt to damage them. Additionally, the roofs can withstand high temperatures as the piles can expand and contract in their layers. These roofs are flexible since the number of layers is variable as desired to reduce costs or address any chosen requirements.

Thermoset Roofs

Thermoset roofs are formed from rubber polymers. The Ethylene Propylene Diene Monomer (EPDM) is commonly used for commercial roofing. Thermoset roofs are a durable roof solution that can withstand ultraviolet rays from the sun and other chemicals. They are easy to maintain and can significantly cut down on cooling costs as they are very energy efficient. 

They typically cost about $10.00 to $12.70 per square foot to replace a thermoset roof.

Thermoplastic Roofs

Thermoplastic roofs are polymers, and the most prominent examples are Thermoplastic Polyolefins (TPO). They are manufactured in the factory and rolled into sheets that can then be fastened and fixed together at the point of application. They are highly energy-efficient and resistant to sunlight rays, chemicals, tears, or the growth of organisms. 

They are good for buildings that emit oils and other chemical materials from their vents. TPO roofs are very durable and flexible, and this means the material can stretch to fit the commercial building’s size and design. The material is recyclable as it can be melted and reformed, thus making it an eco-friendly option. 

The roof is lightweight and great for large commercial buildings. Installing a TPO replacement costs about $11.50 to $14.00 per square foot. 

Factors to consider in changing Commercial Roofs

There are a couple of factors you should consider before you commit to getting a new commercial roof. Commercial roofs are quite heavy on the pockets. As such, you want to make sure you need one. Asides from that, you want to get one that stays for a long time before needing to be replaced. 

In addition to being capital intensive, commercial roof replacements in some buildings mean operations have to be halted to complete the replacement. This is not an exercise you desire to go through frequently. Some of the factors to consider before and while replacing your commercial roof include:

Do you really need a replacement?

If you suspect major damage to your commercial roof and are thinking of getting a replacement, it is necessary to ascertain the extent of the damage. Before you get a contractor to remove and replace your roof, you should first find out if the contractor can fix the damage to your roof. The contractor should inspect the roof for damages due to stagnation of water on the roof, climatic or other similar faults. 

Minor fixes may be required to the drainage system and a localized section of the roof membrane. Ensure you seek out professionals who can give good suggestions about the possibility of a repair or a replacement if unavoidable.

Selecting the roofing material for you

As delineated in the first segment of this article, there are several commercial roofs. You must decide whether to make a replacement and stick to the previous roof (depending on how well it performed) or to opt for a different roof entirely. Additionally, the location you are in and the nature of activities in the building should also factor into choosing a commercial roof.

If you are in climates with warm weather, you should be selecting an insulative material that will keep the building cool. A more durable roof will serve you better for places with strong winds, hail, and other weather factors that can damage the roof. TPO roofs have a strong resistance to chemicals and are good for buildings in which there is the manufacturing of paints, oils, etc., or large industrial kitchens

Cost of the roof

The cost of replacing a commercial roof depends on the roof type, the size of the roof, access to the roof, the slope, and the location you are. The location determines the code regulations and permits needed to work and install the roof. Any additional accessories on the roof may also factor into the bill of replacing your commercial roof. 

Maintenance requirements

In the course of getting your roof replaced, you should keep yourself informed of the maintenance requirements of commercial roofs. A poorly maintained commercial roof will not last as long as it should and will likely keep giving issues. It is essential that while you are getting a replacement, you are planning for future maintenance and how you plan to achieve it.

Maintenance may involve hiring a roof maintenance expert to inspect it annually to address any punctures or tears, clean debris to prevent clogged drains and water damage, and fit any damaged flashings. The expert should complete a routine check of the roofing materials and ensure it is in great condition and address any minor problems as they are noticed. Additionally, inspection and repairs may be needed after major weather events and should be carried out in line with the manufacturer’s warranty.

Professional replacement

Perhaps the most important consideration in getting a commercial roof replaced is getting trusted hands to do the replacement. Commercial roofs not properly installed are very likely to develop defects that eventually call for more repairs and possibly replacement. Roofing contractors with experience in similar projects should be the top point of call for your roof replacement.

Similarly, irrespective of their experience, always ensure you get some warranty for your roof replacement. Commercial roofs have warranties for up to 10 years, during which if any damage occurs not caused by unnatural events, the roofers have to fix it. Such a warranty, alongside a warranty from the manufacturers of the roofing material, leaves you protected against any irregularities, not from your end.

Benefits of Commercial Roof Replacement

A new commercial roof is guaranteed to improve the total well-being of your building. It means better protection from the elements and improved energy efficiency.

Improved Resistance and Durability

When you replace your commercial roof, you effectively make it sturdier and more resilient to the agents of weather. Strong winds, snow, and hail which damage roofs progressively will have lesser effects on the roof. Also, if the roof is properly installed and maintained, you can be guaranteed that your building will be protected from damage to it.

Replacing a commercial roof also means you purchase new flashing, gaskets, and other fittings to the roof. This keeps the roof water-resistant and reduces the risk of growing molds, mildew, and algae damaging it. Depending on the choice of materials, your roof may even be more resistant to storms and winds than it was with the former roof. 

Reduces other costs and increases the value of the building

While the process of replacing a commercial roof is capital intensive, it is an overall economic decision. Changing your roof will automatically translate to a reduction in the need for recurrent repairs and fixes to damage on the roof. This means a lesser cost of maintenance and repairs since you only need to check the roof routinely.

Similarly, commercial roof replacement also means you can now select an insulated roof that can help you cut down on the cost of cooling your entire building. Even if you decide to opt for the same roofing material, thanks to new installation techniques you should still enjoy more benefits of energy efficiency. Newer materials even afford better energy efficiency and can save you a ton of money that will have gone into cooling.

Finally, installing a new commercial roof makes your building more attractive and increases the resale value. If you decide to install a vegetative roof, it symbolizes a statement of sustainability and eco-friendliness that attracts more people to your business. If you decide to part with the building after you have invested in its roof, then you can be assured that you are certain to receive higher offers for the building.


Commercial roofs are large roof systems that cover large buildings such as commercial institutions and industries. Although they are not frequently replaced, their installation should be effectively carried out since they are capital intensive to forestall the chances of defects. This article offers a complete guide and insight into the types of commercial roofs and the factors to consider in replacing a commercial roof. The benefits of getting a new commercial roof are profound, so do it if you need to!   

Technical Writer | Civil Engineer

Olaseeni Ogunniyi is a professional technical writer with over 5 years of experience curating content in the engineering niche. Thanks to his background in Civil Engineering, he has worked as a project manager and a consultant on several roofing projects, from simple hip and gable roofs to more complex combination roofs.

Additionally, he has written several projects on aluminum and metallic roofing sheets and has developed expertise on such topics.