Commercial Asphalt Roof

Commercial Asphalt Roof – Commercial properties often require durable, cost-effective, and easy-to-maintain roofing solutions. One of the most popular systems used in businesses, warehouses, retail buildings, and industrial facilities is the flat roof commercial asphalt roof. Known for its affordability and longevity, asphalt roofing has been trusted for decades as a reliable way to protect flat and low-slope commercial structures.

This guide explores everything you need to know about flat roof commercial asphalt roofing — including its history, construction methods, benefits, drawbacks, maintenance, and whether it’s the right solution for your property.

What is a Flat Roof Commercial Asphalt Roof?

A flat roof asphalt system is a roofing design commonly installed on commercial or industrial buildings with flat or low-slope structures. While the term “flat” is used, these roofs usually have a slight slope (typically ¼ inch per foot) to allow proper water drainage.

Commercial asphalt roofing is built using layers of asphalt, roofing felts, and protective coatings that form a waterproof barrier. It is sometimes referred to as a built-up roofing system (BUR) because it involves multiple layers “built up” to create a strong membrane.

A Brief History of Asphalt Roofing

Asphalt roofing dates back over 100 years and became popular in the early 20th century as a reliable option for large commercial and industrial facilities. The material was chosen because of its:

• Waterproofing abilities – Asphalt naturally repels water.

• Durability – Multiple-ply asphalt systems resist foot traffic and impact.

• Proven performance – With proper maintenance, asphalt roofs can last 20–30 years.

While newer technologies like TPO and EPDM membranes have entered the commercial roofing market, asphalt remains widely used because of its proven track record.

Types of Asphalt Flat Roof Systems

There are several types of asphalt-based flat roof systems. Each is designed for different property needs, budgets, and climate conditions.

Built-Up Roofing (BUR)

The most traditional asphalt roofing system, BUR is made by layering asphalt (hot or cold applied) with felt or fiberglass reinforcement. A gravel or mineral surface is then applied for protection.

• Pros: Long-lasting, great resistance to UV rays and foot traffic.

• Cons: Heavier system; installation requires skilled labor and safety precautions.

Modified Bitumen Roofing

This is an advanced form of asphalt roofing that incorporates polymer modifiers to enhance flexibility and strength. Modified bitumen is typically applied in rolls and can be torch-applied, cold-applied, or self-adhered.

• Pros: Flexible, resistant to cracking, easier to install than BUR.

• Cons: Requires precise installation to avoid leaks at seams.

Asphalt Shingle Roofing (for Low-Slope Areas)

Although less common in large commercial buildings, some smaller offices or mixed-use properties with slightly pitched roofs may use asphalt shingles.

• Pros: Affordable, easy to repair.

• Cons: Not ideal for very flat roofs; shorter lifespan compared to BUR or modified bitumen.

Key Benefits of Asphalt Commercial Roofing

Choosing an asphalt system for your commercial flat roof comes with numerous advantages:

Proven Durability

Asphalt roofing systems have been tested for decades in a variety of climates. When installed correctly, they provide reliable waterproofing and structural protection for 20 years or more.

Cost-Effective Installation

Compared to modern single-ply membranes, asphalt roofing can be more affordable, especially for large facilities. It provides value by combining reasonable upfront costs with long-term performance.

Excellent UV and Fire Resistance

With a gravel or mineral surface, asphalt roofing provides strong resistance to UV rays, reducing sun damage. Many asphalt systems also meet fire-resistant building codes.

Strong Against Foot Traffic

Commercial roofs often require HVAC, plumbing, or electrical technicians to access the roof. Asphalt’s thick, layered system makes it more resistant to punctures and wear from frequent foot traffic.

Versatile Installation Options

Whether applied hot, cold, or with self-adhering sheets, asphalt roofing can be customized to suit building needs and local weather conditions.

Drawbacks of Asphalt Roofing

While asphalt flat roofs are highly reliable, they also come with some challenges:

1. Weight – BUR systems are heavy and may require additional structural support.

2. Labor-Intensive Installation – Hot asphalt requires skilled roofers, safety precautions, and more installation time.

3. Seam Weaknesses – If seams are not properly installed, leaks can occur.

4. Maintenance Requirement – To maximize lifespan, asphalt roofs need regular inspections and minor repairs.

Lifespan and Performance

A properly installed commercial asphalt roof can last:

• BUR systems: 20–30 years

• Modified bitumen systems: 15–25 years

• Shingle systems (on low slopes): 15–20 years

The actual lifespan depends on climate, installation quality, and maintenance. For example, roofs in areas with extreme heat, snow, or heavy rainfall may experience shorter service lives if not regularly maintained.

Maintenance Tips for Flat Roof Asphalt Systems

Regular upkeep is essential for extending the life of your commercial asphalt roof. Here are some key maintenance practices:

1. Semi-Annual Inspections
   Hire a professional roofing contractor to inspect the roof at least twice a year — in spring and fall. This ensures that small issues like cracks or punctures are identified early.

2. Check After Storms
   Severe storms, heavy rains, or high winds can dislodge gravel or damage membranes. Post-storm inspections prevent leaks and water pooling.

3. Clean Debris and Drainage Systems
   Flat roofs are prone to ponding water. Regularly clear drains, gutters, and the roof surface to ensure water flows freely.

4. Reseal Flashing and Seams
   Flashings around vents, HVAC units, and edges should be inspected and resealed to prevent water infiltration.

5. Apply Reflective Coatings
   Reflective coatings can extend roof life by reducing UV damage and lowering energy costs.

Flat Roof Asphalt vs. Other Commercial Roofing Systems

When considering roofing options, it helps to compare asphalt with other popular commercial materials:

• TPO (Thermoplastic Polyolefin): Lightweight, energy-efficient, but less resistant to punctures.

• EPDM (Ethylene Propylene Diene Monomer): Rubber-based, flexible, but seams may be prone to leaks.

• PVC Roofing: Strong chemical resistance, but higher upfront costs.

• Metal Roofing: Extremely durable, but expensive and not ideal for very flat designs.

Asphalt often remains the go-to choice for businesses that need affordability, proven reliability, and durability against foot traffic.

Environmental Considerations

Modern asphalt roofing manufacturers are making strides toward sustainability. Some asphalt products are recyclable, and reflective coatings can reduce heat absorption, lowering energy consumption for air conditioning. While not as eco-friendly as some newer systems, asphalt roofs can still meet green building standards when installed with energy-efficient upgrades.

Choosing the Right Commercial Asphalt Roofing Contractor

Selecting the right roofing contractor is as important as choosing the material. Look for contractors with:

• Proven experience in commercial asphalt roofing installations.

• Licensing and insurance for safety and liability.

• References and case studies of past projects.

• Clear warranties on labor and materials.

Conclusion

A flat roof commercial asphalt roof remains one of the most dependable and cost-effective solutions for businesses. Whether you choose a built-up roofing system or modified bitumen, asphalt offers long-lasting durability, strong waterproofing, and resilience against heavy foot traffic.

By understanding its benefits, potential drawbacks, and maintenance needs, property owners can make informed decisions about protecting their investments. With proper installation and regular care, a commercial asphalt roof can safeguard your building for decades, making it a smart choice for warehouses, retail spaces, and office complexes alike.