Types of Commercial Roofs Explained

Introduction to Commercial Roof Types

When it comes to commercial buildings, your roof does more than just keep the rain out. 

It impacts energy efficiency, long-term maintenance costs, and even the overall lifespan of your property.

Choosing the right commercial roof type can mean the difference between years of worry-free performance and constant, costly repairs.

Whether you’re building new, replacing an old roof, or planning a retrofit, understanding the most common types of commercial roofs will help you make an informed, cost-effective decision. 

In this guide, we’ll break down the top commercial roofing systems, compare their benefits, and give you the insights you need to select the best option for your building.

Types of Commercial Roofs at a Glance

When considering commercial roofing options, it’s important to understand the different types of commercial roofing available for flat or low-slope buildings.

The main types of commercial roofing systems include:

1. Built-Up Roofing (BUR) – A classic flat roofing solution, BUR features a multi-layered “tar and gravel” construction known for its durability and waterproofing.
2. Modified Bitumen (Mod Bit) – Asphalt-based sheets that handle foot traffic well and perform in colder climates.
3. Single-Ply Membranes – A versatile category used primarily on flat or low-slope roofs, offering flexibility and ease of installation.
   • TPO – Reflective, energy-efficient, and popular for low-slope roofs.
   • EPDM – Long-lasting synthetic rubber, great for cold-weather flexibility.
   • PVC Roofing – A durable, flexible, and fire-resistant single-ply membrane, ideal for restaurants and industrial spaces.
4. Metal Roofs – Systems such as standing seam and R-panel metal roofs provide exceptional longevity, weather resistance, and energy efficiency for commercial buildings.
5. Roof Coatings – A cost-effective restoration option to extend the life of an existing roof.
6. Specialty Systems – Options like Spray Polyurethane Foam (SPF) or solar-integrated roofs for energy savings.

Each system comes with its own trade-offs in cost, maintenance, and lifespan. In the next sections, we’ll break down what you need to know about each one.

Commercial Building Roofing Considerations

Selecting the right commercial roofing system for your building is a decision that requires careful consideration of several key factors. Building owners must evaluate not only the type of commercial roofing system, but also how each option aligns with the specific needs of their commercial building. 

For example, metal roofing systems are highly valued for their exceptional durability and ability to withstand high winds, making them ideal for areas prone to severe weather. 

On the other hand, single ply roofing systems are often chosen for their ease of installation, low maintenance requirements, and energy efficiency, which can help reduce long-term operating costs.

The climate and weather conditions in your region play a significant role in determining the best roofing system for your property. 

Additionally, the amount of foot traffic your roof will experience from maintenance crews or HVAC unit servicing should influence your choice, as some commercial roofing materials are better suited to handle regular use without damage.

Other important considerations include the condition of the existing roof deck, the level of insulation required for energy efficiency, and the effectiveness of the roof’s drainage system. 

1. Built-Up Roofing (BUR)

Built-Up Roofing, often called BUR or “tar and gravel” roofing, is one of the oldest and most proven commercial roofing systems. A built up roof consists of alternating layers of asphalt and reinforcing felt, applied in place to create a durable, weather-resistant barrier.

It’s made by layering multiple plies of roofing felt, reinforced with fiberglass or polyester, and sealing them with hot asphalt or bitumen. Bur systems are known for their multi-layered design, which provides excellent durability and resistance to punctures and thermal shock. 

The top is usually covered with gravel or a reflective coating to protect against UV rays. Built up roofs are valued for their longevity and strong weather resistance. During installation, hot mopped asphalt is used to adhere each layer securely to the substrate, ensuring a watertight seal.

Pros of BUR: 

• Durable & Long-Lasting: Can last 20-30 years with proper maintenance.
• Excellent Waterproofing: Multiple layers create a strong moisture barrier.
• Budget-Friendly: Relatively low initial installation cost.
• Good UV Protection: Gravel or reflective coatings reduce sun damage.

Cons of BUR: 

• Heavy System: Requires a roof structure that can support the extra weight.
• Labor Intensive: Installation involves heating asphalt, which is time-consuming.
• Weather-Sensitive Installation: Rain or extreme cold can slow down the process.

BUR is best for flat or low-slope commercial roofs and for building owners who want a proven, budget-conscious system with strong waterproofing.

2. Modified Bitumen (Mod Bit) 

Modified Bitumen (often called Mod Bit) is an evolution of traditional built-up roofing.

Modified bitumen roofing systems combine asphalt with polymer modifiers, such as APP (Atactic Polypropylene) or SBS (Styrene-Butadiene-Styrene), to enhance flexibility, durability, and weather resistance. 

These systems are known for their layered installation and technical performance, making them suitable for various environmental conditions. 

These sheets can be applied using heat (torch-down), cold adhesive, or as self-adhering rolls, making it a versatile option for low-slope commercial roofs.

Pros of Mod Bit:

• Flexible & Durable: Performs well in both hot and cold climates; resists cracking.
• Foot Traffic Ready: Strong surface can handle occasional foot traffic for maintenance.
• Easier Installation than BUR: Fewer layers and multiple application methods.
• Good Waterproofing: Seam overlaps create a tight barrier against leaks.

Cons of Mod Bit: 

• Shorter Lifespan: Typically 10-20 years, shorter than some single-ply or metal options.
• Seam Vulnerability: Improper installation can lead to water intrusion.
• Heat-Related Risks: Torch-down applications require skilled installers for safety.

Mod Bit is best for flat or low-slope roofs needing a balance of durability and cost-efficiency. 

And for building in climates with temperature swings, where flexibility prevents cracking.

3. Single-Ply Membranes: TPO, PVC, EPDM

Single-ply membranes are some of the most popular commercial roofing systems today. A single ply membrane is the core component of these systems, offering flexibility and ease of installation.

They are flexible sheets of synthetic material that are either mechanically fastened, fully adhered, or ballasted to the roof deck. Thermoset membranes, such as EPDM, are a subcategory of single-ply membranes made from rubber polymers, known for their durability and weather resistance.

Each type – TPO, EPDM, and PVC- has unique strengths and best-use cases, making them ideal for commercial flat roofing applications.

3.1 TPO (Thermoplastic Polyolefin)

TPO is a white, reflective membrane known for its energy efficiency and growing popularity on low-slope roofs. It’s heat-welded at the seams, creating a watertight barrier.

Pros of TPO: 

• A highly reflective surface reduces cooling costs
• Lightweight and relatively easy to install
• Resistant to UV, punctures, and chemicals
• Eco-friendly: recyclable and heat-welded seams reduce leaks

Cons of TPO: 

• Lifespan ~ 10-25 years, which is shorter than EPDM or metal
• Can shrink or fail at seams if installed improperly

TPO is best for energy-conscious buildings in warmer climates, and low-slope commercial roofs need a cost-effective solution.

3.2 EPDM (Ethylene Propylene Diene Monomer)

EPDM is a synthetic rubber membrane that has been a go-to for commercial flat roofs for decades. An EPDM roof is a single-ply membrane made from ethylene propylene diene monomer, typically available in 45 or 60 mil thickness, and is installed using adhesive or seam tape rather than heat welding. EPDM roofing is valued for its durability, flexibility, and cost-effectiveness, making it a popular choice for commercial roofing systems, especially in climates with temperature fluctuations. Rubber roofing, including EPDM, is known for its resilience against UV rays, chemicals, and harsh weather, and is widely used in low-slope commercial applications due to its long-lasting performance.

It’s available in black (absorbs heat) or white (reflects heat) and comes in large rolls to minimize seams.

Pros of EPDM:

• Extremely durable with a 20-40 year lifespan
• Excellent flexibility in cold temperatures, resists cracking.
• Economical installation and maintenance
• Large sheets mean fewer seams and reduced leak risk

Cons of EPDM:

• Standard black EPDM can increase cooling costs in hot climates
• Vulnerable to punctures if unprotected
• Appearance is less aesthetic compared to TPO or metal

EPDM is best for commercial buildings in cold or variable climates and for budget-conscious owners who want longevity and reliability.

3.3 PVC (Polyvinyl Chloride)

PVC membranes are known for chemical, fire, and wind resistance, making them a favorite for restaurants, industrial buildings, and facilities with exposure to oils or harsh conditions.

PVC roofing is a single-ply membrane made of Polyvinyl Chloride, offering excellent durability, flexibility, and UV resistance, as well as superior fire resistance and weldability compared to other roofing types like TPO and EPDM. 

Like TPO, PVC membranes are heat-welded for strong seams.

Pros of PVC:

• 15-30 year lifespan with excellent durability
• Superior resistance to chemicals, grease, and fire
• Highly reflective, energy-efficient surface
• Welded seams are strong and watertight

Cons of PVC:

• Higher upfront cost than TPO or EPDM
• Can become brittle over decades without maintenance

PVC is best for restaurants, factories, and facilities with chemical exposure.

4. Metal Roof Systems

Metal roofs are a high-performance option for commercial buildings, offering exceptional durability and energy efficiency.

Standing seam roofing, a popular type of metal roof, features interlocking panels that ensure superior water drainage and help prevent ponding and leaks. 

Metal roofs are also known for their excellent heat resistance, withstanding high temperatures and UV exposure to maintain performance and extend lifespan.

It’s typically installed as standing seam panels or corrugated metal sheets, with a protective coating to resist rust, UV rays, and harsh weather.

Pros of Metal Roofing: 

• Long Lifespan: 40-60 years or more with proper maintenance
• Energy Efficient: Reflective coatings reduce heat absorption and cooling costs
• Low Maintenance: Minimal upkeep compared to traditional flat roofs
• Highly Durable: Resistant to wind, fire, and extreme weather

Cons of Metal Roofing: 

• Higher Upfront Cost: The Initial investment is higher than most flat roof systems
• Noise Concerns: Rain and hail can be loud without proper insulation
• Expansion & Contraction: Temperature changes can affect panel movement if not installed correctly

Metal roofing is best for commercial buildings needing long-term performance and low maintenance. As well as sloped or low-slope roofs where water can run off easily.

5. Roof Coating Systems

Roof coatings are a cost-effective way to extend the life of an existing commercial roof without a full replacement. 

These liquid-applied systems create a seamless, waterproof membrane over the current roof, sealing small leaks and improving energy efficiency. 

Common coating types include silicone, acrylic, and polyurethane. 

Pros of Roof Coatings:

• Cost-Effective: Cheaper than full roof replacement
• Extends Roof Life: Adds 10-20 years to your existing roof
• Energy Efficient: Reflective coatings can reduce cooling costs
• Seamless & Waterproof: Protects against ponding water and minor leaks

Cons of Roof Coatings: 

• Not for Severely Damaged Roofs: Works best on roofs in fair condition
• Regular Inspections Needed: Coatings can wear or peel over time
• Weather Dependent Application: Needs dry conditions for proper curing

Roof coatings are best for owners looking to restore rather than replace their roof and for flat or low-slope roofs with minor leaks or aging surfaces.

6. Specialty Systems (Emerging Options)

Some commercial buildings require unique roofing solutions beyond standard flat or sloped systems.

Specialty roofing systems are designed for specific performance needs, like maximum insulation, energy production, or seamless waterproofing. Selecting the right commercial roof system is essential to meet the unique requirements of each building, considering factors such as durability, energy efficiency, and maintenance.

Specialty systems include options for low slope roofing, which are specifically engineered for any low slope roof (defined as a roof with a slope of three inches per foot or less), ensuring proper drainage and preventing water ponding. 

Some specialty systems are also suitable for residential flat roofs, providing enhanced insulation and longevity. 

Common specialty options include:

6.1 Spray Polyurethane Foam (SPF)

SPF is a liquid-applied roofing material that expands into a seamless, insulating foam. 

Pros:

• Seamless waterproof barrier
• High R-value for energy savings
• Can be applied over existing roofs

Cons:

• Requires skilled installation
• Can be damaged by UV without a protective coating

SPF is best for flat roofs needing insulation and leak prevention.

6.2 Solar-Integrated Roofing

Solar panels can be integrated into metal or flat roof systems to generate on-site energy.

Pros: 

• Reduces energy bills and carbon footprint
• Can pair with tax incentives or energy credits

Cons: 

• High upfront cost
• Requires proper roof structural support

Solar-integrated roofing works best with energy-conscious businesses with long-term sustainability goals.

Some facilities use custom solutions like cool roofs, reflective membranes, or hybrid systems that combine multiple roofing technologies for enhanced performance. 

Best Practices & Maintenance Tips

No matter which commercial roof type you choose, proper maintenance is key to maximizing its lifespan and preventing costly repairs. Many commercial buildings use flat roofs for their cost-effectiveness, ease of maintenance, and ability to accommodate rooftop equipment like HVAC units.

 To protect your commercial property and its value, ensure your commercial roof installations are completed by professionals who follow best practices and that the roof is installed properly to minimize repairs and maximize lifespan. Regular inspections and maintenance of the entire roof system are crucial for long-term performance.

Here are some best practices every building owner should follow:

Schedule Regular Inspections

• Inspect your roof at least twice a year, typically in spring and fall.
• Look for cracks, punctures, standing water, or loose seams.

Keep Roof Surfaces Clear

• Remove debris like branches, leaves, and dirt to prevent water pooling.
• Check and clear drainage systems, gutters, and scuppers regularly.

Address Small Issues Immediately

• Patch minor leaks or punctures before they become larger problems.
• Reapply sealant or coating where wear is visible.

Maintain Flashing and Seams

• Seams and flashing are the first points of failure on many roofs.
• Ensure they are tightly sealed and repair any gaps right away.

Consider Preventive Coatings

• Reflective coatings or protective overlays can extend roof life by 5-10 years.
• Ideal for single-ply, metal, and older BUR/Mod Bit systems.

Work with Certified Contractors

• Regular professional inspections ensure warranty compliance.
• Certified roofers can spot issues that building staff may miss.
• Mechanical contractors should be mindful when accessing the roof for equipment servicing, as their activities can affect the roof’s condition and maintenance needs.

Conclusion

Choosing the right commercial roof type isn’t just about protecting your building. It’s about protecting your investment.

From budget-friendly BUR and Mod Bit systems to energy-efficient TO and PVC membranes. Each roof type offers unique advantages depending on your building’s needs, climate, and long-term goals.

No matter which system you choose, proper installation and regular maintenance are the keys to maximizing lifespan and minimizing repair costs.

If you’re planning a new installation, replacement, or just need an expert inspection, Eagle Crest Construction can help you:

• Assess your current roof condition
• Compare the best roof types for your building
• Deliver a reliable, long-lasting installation

Protect your property and your bottom line. 

Contact Eagle Crest today for a free commercial roof assessment!