Commercial Asphalt Roof

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Commercial Asphalt Roof – Commercial roofing is a critical investment for businesses, as it directly impacts building durability, energy efficiency, and long-term maintenance costs. Among the many roofing systems available, commercial asphalt roofing has remained one of the most popular and trusted options. Known for its versatility, affordability, and durability, asphalt-based systems are widely used in commercial buildings of all sizes, from small retail stores to large industrial complexes.

This article provides a detailed overview of commercial asphalt roofing, including its history, types, benefits, installation process, cost considerations, maintenance requirements, and comparisons with other roofing systems.

Understanding Commercial Asphalt Roofing

Asphalt has been a staple roofing material for over a century. Derived from petroleum, it is a sticky, black, semi-solid substance that, when combined with fiberglass mats or organic felts, creates strong and waterproof roofing membranes. Commercial asphalt roofing is especially popular in low-slope and flat roof applications, where water resistance and long-term performance are crucial.

Unlike steep-slope asphalt shingles used on homes, commercial asphalt roofing typically comes in the form of built-up roofing (BUR) systems or modified bitumen (mod-bit) systems. Both offer unique benefits and are tailored for different building needs.

Types of Commercial Asphalt Roofing

Built-Up Roofing (BUR)

BUR, also known as “tar and gravel roofing,” is the oldest and most traditional type of commercial asphalt roof. It consists of multiple layers (or “plies”) of asphalt-saturated felt alternated with bitumen and topped with a layer of gravel or mineral surfacing.

Key Features of BUR:

  • Multiple protective layers provide excellent waterproofing.

  • Gravel or aggregate top layer shields against UV rays and physical damage.

  • Highly durable, lasting 20–30 years with proper care.

  • Excellent fire resistance due to its layered structure.

Modified Bitumen (Mod-Bit)

Developed in the 1960s to improve on traditional BUR, modified bitumen roofing combines asphalt with polymer modifiers such as APP (atactic polypropylene) or SBS (styrene-butadiene-styrene). This creates a more flexible and durable material.

Key Features of Mod-Bit:

  • Greater elasticity, making it resistant to cracking in cold temperatures.

  • Can be installed using multiple methods (torch-applied, self-adhered, cold-applied adhesives, or hot asphalt).

  • Available in smooth or granulated finishes for additional UV protection.

  • Easier to repair and maintain compared to BUR.

Asphalt Shingles (Limited Use in Commercial)

While asphalt shingles are primarily used in residential settings, they may occasionally be applied to steep-slope commercial buildings such as small offices, churches, or retail stores.

Benefits of Commercial Asphalt Roofing

Affordability

Asphalt roofing systems are cost-effective compared to alternatives like metal, TPO, or EPDM. Their lower upfront costs make them attractive for businesses seeking reliable roofing without overspending.

Durability

With proper installation and maintenance, asphalt roofs can last 20–30 years. Their layered structure provides resilience against harsh weather conditions, including heavy rains, hail, and high winds.

Versatility

Asphalt roofing can adapt to a wide variety of commercial building types and sizes. Whether it’s BUR for maximum durability or mod-bit for enhanced flexibility, asphalt roofing can be tailored to different business needs.

Proven Track Record

Asphalt has been used for commercial roofing for more than 100 years, giving it a long history of reliability and performance.

Energy Efficiency

When paired with reflective coatings or light-colored surfacing, asphalt roofing can reduce heat absorption, helping lower cooling costs in commercial buildings.

Low Maintenance

Although regular inspections are recommended, asphalt roofs are relatively easy and inexpensive to maintain compared to some other roofing systems.

Installation Process of Commercial Asphalt Roofing

The installation process depends on the type of asphalt roofing system chosen.

For BUR Systems:

  1. Surface Preparation – The roof deck is cleaned, dried, and inspected for damage.

  2. Base Sheet Installation – A base sheet is installed as the first layer of protection.

  3. Layering – Several alternating layers of asphalt and felt are applied.

  4. Surfacing – The system is topped with gravel or a mineral coating for durability and UV protection.

For Modified Bitumen Systems:

  1. Deck Preparation – Ensuring the deck is smooth, clean, and primed.

  2. Application Method – Depending on the system, installers may use torches, hot asphalt, adhesives, or peel-and-stick sheets.

  3. Sealing – Proper sealing of seams and edges to prevent leaks.

  4. Final Coating – Optional reflective coatings can be applied for energy efficiency.

Cost of Commercial Asphalt Roofing

The cost of commercial asphalt roofing varies depending on several factors:

  • Type of system (BUR is typically more expensive due to labor-intensive installation, while mod-bit can be more cost-efficient).

  • Roof size and slope (larger roofs or complex designs cost more).

  • Material quality (premium modified bitumen membranes cost more).

  • Labor costs (vary by region and contractor expertise).

Average Costs (per square foot):

  • BUR: $4 – $7

  • Modified Bitumen: $3.50 – $6

  • Asphalt Shingles (steep slope commercial): $2.50 – $5

For a 20,000-square-foot commercial roof, the cost can range from $70,000 to $140,000 or more, depending on specifications.

Maintenance of Commercial Asphalt Roofing

Routine maintenance is essential to maximize the lifespan of asphalt roofing systems. Common practices include:

  1. Regular Inspections

    • At least twice a year and after severe weather events.

    • Check for cracks, blisters, loose gravel, or punctures.

  2. Cleaning

    • Remove debris, leaves, and standing water to prevent drainage issues.

  3. Sealant Reapplication

    • Reseal flashings, seams, and penetrations to prevent leaks.

  4. Prompt Repairs

    • Address small issues immediately before they escalate into major problems.

With consistent care, commercial asphalt roofs can exceed their expected lifespans.

Comparisons With Other Roofing Systems

Asphalt vs. TPO (Thermoplastic Polyolefin)

  • TPO is highly reflective and energy-efficient but relatively new compared to asphalt.

  • Asphalt offers proven longevity and easier repairs, though it may absorb more heat without coatings.

Asphalt vs. EPDM (Ethylene Propylene Diene Monomer)

  • EPDM is durable and weather-resistant, often lasting longer (up to 40 years).

  • Asphalt is more cost-effective upfront and provides better protection against punctures.

Asphalt vs. Metal Roofing

  • Metal roofs can last 40–60 years and require little maintenance, but they are significantly more expensive.

  • Asphalt roofing offers a balance of affordability and performance, making it more practical for many businesses.

Sustainability and Environmental Considerations

While asphalt is petroleum-based, recycling initiatives have grown in recent years. Old asphalt roofing materials can often be recycled into new roofing products or even repurposed for paving. Additionally, reflective coatings help improve sustainability by reducing urban heat island effects and lowering energy consumption.

Is Commercial Asphalt Roofing Right for Your Business?

Choosing a commercial roofing system depends on multiple factors, including budget, building design, climate, and long-term goals. Asphalt roofing is ideal for:

  • Businesses seeking a cost-effective yet reliable system.

  • Low-slope or flat roof buildings requiring durability and waterproofing.

  • Companies prioritizing a proven material with decades of performance history.

However, businesses with long-term sustainability goals or those located in extreme climates may also consider alternative roofing materials alongside asphalt.

Conclusion

Commercial asphalt roofing remains a cornerstone of the roofing industry due to its affordability, durability, and proven performance. With options like built-up roofing and modified bitumen, businesses have flexibility in choosing a system that best suits their needs. Proper installation and regular maintenance can ensure these roofs last decades, providing reliable protection for commercial investments.

For business owners evaluating roofing options, asphalt roofing continues to be a trusted, cost-effective, and versatile solution—one that has stood the test of time and continues to evolve with modern technology and sustainability practices.