When your commercial property’s roof approaches the end of its service life, selecting the appropriate roofing material becomes crucial. The market offers a plethora of options, each with unique advantages and considerations. Assessing your building’s specific requirements is the foundational step in this process. By the end of the article you’ll have a better understanding of the 5 commercial roofing types. The pros and cons of each. And hopefully you can make a well-informed decision about your next commercial roof investment.

Different types of commercial roof construction

Types of Commercial Roof Construction

In the realm of commercial building roofing, there exist distinct methods tailored to different structural needs and preferences.

Flat Roof Commercial Construction 

Flat roof systems are highly favored in commercial settings due to their versatility, enabling architects and engineers to maximize space efficiency. The absence of surrounding area for rooftop equipment necessitates strategic planning and design expertise. Modern flat roof systems mandate a slope to ensure proper drainage, achieved through specialized insulation techniques. Tapered insulation plays a crucial role here, facilitating both effective water runoff and enhancing thermal insulation properties, denoted by its R-value. However, the integration of tapered insulation entails increased project costs.

Low Slope Commercial Construction

Low slope roofs are engineered with a slight incline to facilitate water drainage. While effective for drainage purposes, this construction type poses challenges for certain materials. For instance, installing metal on a low slope roof can lead to issues such as leakage and heightened maintenance demands, issues not typically encountered with alternative roofing systems.

Steep Slope Commercial Construction 

Steep slope roofs in commercial applications closely mirror residential construction methods. Predominant designs include gable and hip roofs, often structured using materials like metal or wood trusses. Alternatively, custom framing utilizing 2x wood framing material is also viable. This approach lends itself to a more traditional aesthetic while ensuring structural integrity suitable for commercial environments.

Workers installing a commercial roof

Key Factors Influencing Commercial Roofing Installation 

Lifespan Desired

Determining the optimal type of commercial roof begins with assessing the lifespan required for your building. Are you looking for a robust solution that lasts decades, or a shorter-term option? The longevity of the roof directly influences the choice of materials and construction techniques. Factors such as weather conditions and maintenance schedules play critical roles in this decision-making process.

Durability Requirements 

Consider the operational demands placed on your commercial roof. Are there frequent service visits from mechanical contractors accessing HVAC units, vents, or satellite systems? Does foot traffic significantly impact the roof’s integrity? These aspects dictate the durability needed from the roofing material. Selecting the appropriate thickness and type ensures longevity and minimizes maintenance costs over time.

Energy Efficiency Standards 

In today’s environmentally conscious landscape, energy efficiency is paramount. Many governmental and institutional projects mandate specific energy efficiency ratings for commercial roofs. The introduction of EPS tapered insulation, for instance, enhances the roof’s thermal performance, thereby reducing heat penetration into the building. Understanding these requirements is crucial when selecting materials to meet or exceed prescribed energy efficiency standards.

Cost Considerations

While quality and durability are non-negotiable, cost efficiency remains a pivotal consideration. The initial investment in materials, installation, and maintenance should align with your budgetary constraints. Balancing upfront expenses with long-term savings through reduced energy costs and minimal repairs is key to achieving cost-effectiveness in commercial roof installations.

Five different commercial roofs

Top 5 Commercial Roof Types 

Single-Ply Roofing 

Single-ply roofing represents a prevalent choice for both commercial and residential flat roofs due to its versatility and durability. These roofing systems, available in various materials such as TPO, PVC, and EPDM, offer distinct advantages tailored to different needs.

Thickness Options Explained 

When considering single-ply roofing, thickness becomes a critical factor influencing performance and longevity. Contractors often discuss thickness in terms of mils (thousandths of an inch), offering options like 45 mil or 60 mil roofs. The higher the mil number, the thicker the roofing material, providing enhanced durability and often correlating with longer manufacturer warranties.

Understanding TPO Roofing 

Thermoplastic Polyolefin (TPO) roofing systems are known for their environmental benefits and energy efficiency. Made from a blend of rubber and plastic, TPO roofs offer superior resistance to UV rays and weathering, making them a sustainable choice for many property owners.

PVC Roofing Systems 

Polyvinyl Chloride (PVC) roofing systems are noted for their exceptional durability and resistance to chemicals, making them ideal for environments where industrial pollutants or rooftop chemicals may be a concern. PVC roofs also offer excellent fire resistance and are easy to maintain, contributing to their popularity in commercial settings.

Modified Bitumen (Rubber Roofing or Mod-Bit) 

Modified bitumen, often referred to as Mod-Bit or rubber roofing, represents the evolution of commercial flat roofing beyond traditional built-up or hot tar systems. While hot tar roofing has been a staple, the complexities and hazards involved in heating asphalt to extreme temperatures have led to a shift towards more advanced roofing technologies like modified bitumen.

Installation Methods 

Modified bitumen roofs can be installed using various methods tailored to different project needs:

Hot Tar Applied 

Involves heating asphalt to high temperatures for application, traditionally used but less popular due to safety concerns and labor-intensive requirements.

Cold Tar Applied 

A safer alternative where modified bitumen sheets are adhered using cold-applied adhesives, reducing risks associated with high-temperature materials.

Torch Applied 

Utilizes a torch to heat and adhere the modified bitumen sheets, providing a strong bond and efficient installation process suitable for many commercial applications.

Self-Adhered

Represents a significant advancement, allowing for straightforward installation without the need for heating equipment or adhesives, enhancing efficiency and reducing installation time.

Advantages of Modified Bitumen Roofing 

One of the primary advantages of modified bitumen roofing lies in its multilayered composition, which enhances durability and longevity. This feature makes it particularly suitable for commercial roofs subjected to high foot traffic and varying weather conditions.

Disadvantages of Modified Bitumen Roofing 

However, the increased durability and complexity of multilayered modified bitumen roofing come at a cost. The materials and labor required for installation are generally higher compared to simpler roofing systems. Additionally, maintenance and repairs can be more intricate and costly due to the layered structure of the roof system.

Built-Up Roofing (Hot Tar Roofing) 

Built-Up Roofing (BUR), commonly known as hot tar roofing, earns its name from the process of layering materials to create a robust roof system. This method involves alternating plies of fiberglass roofing rolls and hot asphalt (tar) between each layer.

Installation Process

The installation of a built-up roof is a meticulous process that begins with heating asphalt to temperatures nearing 500 degrees Fahrenheit. Once heated, the asphalt is applied directly onto the roof deck or insulation using a mop, similar to how one would mop a kitchen floor. Between each application of hot asphalt, layers of roofing material are rolled out and embedded into the asphalt while it is still hot. Depending on the requirements, built-up roofs typically consist of 4 to 6 layers.

Importance of the Top Layer 

Among all the layers, the topmost layer plays a crucial role in the maintenance and repair of the roof. Often, this top layer is a flood coat of hot asphalt mixed with gravel or rocks while the asphalt is still hot. This finish not only enhances durability but also presents challenges in repair, requiring skilled roofers to ensure longevity and effectiveness.

Modified Bitumen Flat Roofing 

Roofs that feature a granule surface cap sheet or an asphalt flood coat are easier to maintain and repair compared to those with gravel finishes. The condition of this top layer is critical; it must have sufficient lifespan remaining to support effective repairs that endure.

Advantages and Disadvantages

Built-up roofs are renowned for their longevity, typically lasting 20 to 30 years due to their durable construction that withstands heavy foot traffic without damage. However, the initial installation cost is a drawback, as the process involves multiple layers and extensive labor. Moreover, the use of hot asphalt presents safety risks during application, especially on larger buildings where significant roof areas are covered.

Metal Roofing 

Metal roofing stands out as a favored choice among commercial buildings, blending aesthetic appeal with exceptional durability.

Types of Metal Roof Systems 

There exist two primary categories of metal roof systems:

Standing Seam Metal Roofing 

Standing seam roofs feature concealed fasteners, providing a sleek, uninterrupted appearance. They excel in longevity, often surpassing 50 years with proper installation. Known for high wind resistance, they withstand severe weather conditions without detachment. Although they enhance building aesthetics and value, their installation complexity translates to higher costs and demands skilled craftsmanship, particularly for flashing integration.

Screw-Down Metal Roofing 

In contrast, screw-down metal roofs utilize exposed fasteners penetrating the roofing material. They offer economic benefits and contribute to curb appeal. However, they necessitate maintenance within approximately five years due to thermal movement causing screws to loosen over time.

Commonly Used Metal Roofing Materials 

Over the past three decades, three main metal roofing materials have dominated the commercial sector in the United States:

  • Aluminum
  • Steel
  • Galvalume

These materials are renowned for their economic viability and diverse aesthetic options, spanning from standing seam to screw-down and even shingle-style profiles.

Aluminum Metal Roofing 

Aluminum stands out as a premier choice among energy-efficient metal roofing materials. It boasts versatility in thickness, typically available in .032, .040, or .050 gauges, each serving different structural needs. A higher gauge number indicates increased thickness, ensuring robust durability suitable for diverse roofing applications.

Thickness Varieties and Applications 

Aluminum roofing comes in several thickness options—.032 and .040 gauges are particularly favored in commercial settings for their optimal balance of weight and resilience. For projects requiring heightened durability, the .050 gauge provides added strength, ensuring prolonged performance under varying environmental conditions.

Benefits of Aluminum Roofing 
  • Energy Efficiency: Reflective properties of aluminum reduce heat absorption, promoting energy savings by maintaining cooler indoor temperatures.

  • Durability: High resistance to corrosion and weathering extends the roof’s lifespan, reducing maintenance costs and enhancing long-term reliability.

  • Environmental Impact: Aluminum is recyclable, contributing to sustainable building practices and minimizing environmental footprint.

Steel Metal Roof 

Steel roofing stands out as the predominant choice for commercial buildings seeking durable, cost-effective roofing solutions. Composed of galvanized steel, which undergoes a process of hot-dipping or zinc coating, steel roofing combines affordability with robust performance.

Types of Steel Used in Roofing 

Steel used in roofing typically ranges in gauge, including 24, 26, and 29 gauges. Contrary to aluminum, where higher numbers denote thicker material, with steel, lower numbers indicate greater thickness and durability.

Common Profiles of Steel Roofing 

Steel roofing is available in various profiles tailored for commercial properties:

  • Standing Seam Metal Panels
      • Features: Panels are 12”-18” wide with concealed fasteners.
      • Benefits: Promotes sleek aesthetics and excellent weather resistance.

  • Interlocking Steel Shingles
      • Features: Resembles slate or shake with concealed fasteners.
      • Benefits: Offers a traditional look with modern durability.

  • 5-V Crimp Metal Roofing
      • Features: 2-foot wide panels with exposed fasteners.
      • Benefits: Provides a distinctive appearance and ease of installation.

  • R-Panels or Multi-Rib Panels
    • Features: 3-foot wide panels with exposed fasteners.
    • Benefits: Ideal for large-scale commercial applications due to efficiency in installation.

Galvalume Metal Roof 

Galvalume metal roofing is an innovative material composed of a steel core coated with a corrosion-resistant aluminum-zinc alloy. This combination provides exceptional durability and longevity, making it a popular choice in the construction industry.

Properties of Galvalume Metal 

Galvalume metal shares similarities with traditional steel roofing, offering options in various thicknesses such as 24 gauge, 26 gauge, or 29 gauge. It is also available in multiple panel profiles, catering to diverse architectural and functional requirements.

Advantages of Galvalume Metal Roofing 
  • Cost-Effectiveness: Unlike painted finishes, Galvalume boasts a mill finish that reduces costs without compromising on quality. This affordability makes it an economical choice for both residential and commercial projects.

  • Durability and Resilience: Its aluminum-zinc coating provides superior corrosion resistance, particularly advantageous in coastal or saltwater environments where traditional materials may corrode over time.

  • Ease of Installation: The inherent toughness of Galvalume metal makes it easier to handle during installation compared to painted materials, which are prone to scratches and require careful handling.

Asphalt Shingles (Upgraded or Designer Shingles)

Versatility of Asphalt Shingles

Asphalt shingles are a staple in residential roofing. They are probably adorning your roof and mine. Beyond homes, these shingles are extensively utilized in commercial buildings. Their versatility and practicality make them a go-to option for various construction projects.

Designer Shingles for Commercial Use

Commercial buildings do not settle for builder-grade shingles. These basic shingles are typically seen in new residential constructions. Builder-grade shingles, while cost-effective, offer minimal wind protection and demand replacement every 10 to 12 years. They simply don’t meet the robust requirements of commercial structures.

Advantages of Upgraded Shingles

Upgraded or designer shingles are the preferred choice for commercial roofs. These premium shingles provide superior wind resistance, which is crucial for the durability of large structures. They enhance the building’s exterior aesthetics, adding significant curb appeal. Most importantly, designer shingles boast a lifespan of 25 to 35 years, offering longevity and reducing the frequency of replacements.

Challenges of Shingle Replacement

However, the longevity of any shingle has its limits. Replacement becomes inevitable. This process can be particularly challenging in commercial settings. Navigating around tenants or customers during a roof replacement can be a logistical nightmare. The project can be messy and disruptive, requiring careful planning and execution to minimize inconvenience.

Modern commercial building roof with metal and solar panels

What’s the Optimal Roofing Solution for Your Commercial Building?

When your commercial property demands a roof replacement or you’re deliberating over the ideal roofing for a new construction venture, it’s crucial to weigh several pivotal factors:

Foot-Traffic Durability

Your commercial roof must endure varying levels of foot traffic. Frequent maintenance visits, HVAC installations, and routine inspections necessitate a robust roofing material that resists wear and tear. Consider reinforced membranes or durable metal roofing solutions to withstand continuous use without compromising structural integrity.

Energy Efficiency 

Optimizing energy efficiency is paramount in reducing operational costs. Reflective roofing materials, such as TPO or cool roofing solutions, can significantly diminish cooling expenses by deflecting solar radiation. Insulation plays a critical role; superior insulation materials reduce heat transfer, maintaining a stable indoor climate and enhancing overall energy performance.

Resistance to Grease and Chemicals

Commercial kitchens and industrial facilities often expose roofs to grease and chemical spills. Selecting a roofing system with excellent chemical resistance, such as PVC or specific types of EPDM, ensures longevity and mitigates potential damage from these harsh substances. Protective coatings can also be applied to enhance resistance.

Wind Resistance 

In regions prone to high winds, the roof’s resilience against uplift forces is crucial. Built-up roofing (BUR) systems, along with metal roofs secured with interlocking panels, offer exceptional wind resistance. Adhered or mechanically fastened single-ply membranes also provide robust solutions, safeguarding your investment from severe weather conditions.

Sun Exposure 

Persistent sun exposure accelerates roofing material degradation. UV-resistant options, such as modified bitumen or specialized coatings, extend the lifespan of your roof. These materials reflect harmful rays, reducing thermal expansion and contraction cycles that lead to premature wear.

Visibility of the Roof 

The aesthetic visibility of your roof may influence your choice. For businesses where the roof is a prominent visual element, architectural metal roofing or aesthetically pleasing single-ply membranes can enhance the building’s appearance. This is particularly relevant for commercial entities aiming to project a professional and polished image.

Budget Considerations 

Balancing cost and quality is often the primary concern. While initial expenditures for high-end materials like metal or green roofs may be substantial, their long-term benefits, including durability and reduced maintenance costs, often justify the investment. Conversely, budget-friendly options like asphalt shingles or basic single-ply membranes offer adequate performance for less demanding applications.

Longevity 

Longevity correlates directly with material choice and maintenance practices. Metal roofs can last upwards of 50 years with proper care, whereas single-ply membranes might require replacement after 20-30 years. Opt for materials with proven durability and consider lifecycle costs to make an informed decision that aligns with your long-term financial planning.

Climate and Usage 

The building’s intended use and the regional climate heavily influence the optimal roofing choice. For instance, in colder climates, materials that perform well under snow and ice loads, such as modified bitumen, are advisable. Conversely, in hot, arid regions, reflective materials that combat intense heat are more suitable.

 

Empowered with this knowledge, you can confidently select the ideal roofing solution for your commercial building. For further guidance, explore our comprehensive resources available in our learning center, designed to support your roofing decisions with expert insights and detailed information.

Conclusion

Selecting the optimal roofing material for your commercial property is a significant decision that impacts the building’s longevity, energy efficiency, and overall functionality. By understanding the pros and cons of various commercial roofing types and considering key factors such as durability, energy efficiency, and cost, you can make an informed choice that aligns with your specific needs and budget. Whether you opt for single-ply systems, modified bitumen, built-up roofing, metal roofing, or asphalt shingles, each option offers unique benefits and challenges. Ultimately, the best roofing solution is one that meets your building’s demands and enhances its structural integrity and performance over time.

FAQs

  • What is the best roofing material for energy efficiency?
    Thermoplastic Polyolefin (TPO) roofing is highly regarded for its energy efficiency due to its reflective properties, which reduce heat absorption and help maintain cooler indoor temperatures.

  • How long does a commercial metal roof typically last?
    Commercial metal roofs, especially those made from aluminum or Galvalume, can last upwards of 50 years with proper installation and maintenance.

  • What are the main advantages of modified bitumen roofing?
    Modified bitumen roofing is known for its durability and multilayered composition, making it ideal for roofs subjected to high foot traffic and varying weather conditions. It offers excellent waterproofing and longevity.

  • Are asphalt shingles suitable for commercial buildings?
    Yes, upgraded or designer asphalt shingles are suitable for commercial buildings. They provide superior wind resistance, enhance curb appeal, and offer a lifespan of 25 to 35 years, making them a practical choice for many commercial applications.

  • What factors should be considered when choosing a commercial roof?
    Key factors include foot-traffic durability, energy efficiency, resistance to grease and chemicals, wind resistance, sun exposure, aesthetic visibility, budget considerations, longevity, and the regional climate and intended use of the building.