Common Types of Commercial Roofing Systems

Choosing the right commercial roofing system is essential for ensuring durability, energy efficiency, and cost-effectiveness. The roof serves as the first line of defense against the elements, impacting the building's performance, maintenance costs, and overall value. With various options available, selecting the best system can be challenging. 

This blog will explore some common types of commercial roofing systems, highlighting their unique benefits and considerations. From durable metal roofs to sustainable green roofing, we’ll cover a range of options to help you make an informed decision based on your building's specific needs.

Flat Roof Systems

Flat roofs are a popular and practical choice for many commercial buildings, including warehouses, office complexes, and retail stores, thanks to their cost-effectiveness and efficient design. These roofs are characterized by a minimal slope, usually less than 10 degrees, allowing for easier water drainage. 

This design helps reduce construction costs and provides more usable space for building systems, such as HVAC units, or even for additional green roofs or recreational areas. However, flat roofs do require careful attention to drainage and maintenance to avoid issues such as water pooling. Below are common materials used:

• TPO (Thermoplastic Olefin): TPO is a highly energy-efficient material known for its ability to reflect sunlight, which helps reduce cooling costs. It also offers excellent UV resistance and durability, making it ideal for areas with high sun exposure.
  
• EPDM (Ethylene Propylene Diene Monomer): EPDM is a long-lasting, rubber-based material that is resistant to UV radiation, extreme weather conditions, and ozone. It is one of the most durable options for flat roofs, providing protection for up to 30 years.
  
• PVC (Polyvinyl Chloride): PVC roofing systems are known for their strength and resistance to harsh chemicals and weather conditions. These roofs offer excellent durability, especially in environments exposed to industrial pollutants or high foot traffic.

Low-Slope Roofing Systems

Low-slope roofs are a popular choice for many commercial buildings, including office complexes, retail spaces, and industrial warehouses. These roofs are similar to flat roofs but feature a slightly steeper incline, typically ranging from 10 to 30 degrees. 

The increased slope improves water drainage, which helps to reduce the risk of water ponding and enhances the overall durability of the roof. This makes low-slope roofs a reliable option for structures that need to withstand varying weather conditions while offering easy installation and long-term performance. Below are common materials used:

• Modified Bitumen: Modified bitumen is a common material for low-slope roofing. This material is composed of layers of bitumen (asphalt) reinforced with fabric, making it highly durable and resistant to weathering. It is also relatively easy to install and provides excellent protection against water infiltration.
  
• Built-Up Roofing (BUR): Built-up roofing systems are made up of multiple layers of bitumen and reinforcing fabrics. These systems provide excellent waterproofing, durability, and resistance to UV rays, making them a long-lasting option for low-slope roofs.
  
• Metal Roofing: Metal panels made from materials like aluminum or steel are often used for low-slope roofs due to their strength, longevity, and resistance to harsh weather conditions, including wind, snow, and rain. Metal roofing is also energy-efficient, reflecting sunlight and reducing cooling costs.

Metal Roofing Systems

Metal roofing systems are highly regarded for their durability, longevity, and aesthetic appeal, making them a popular choice for commercial, industrial, and agricultural buildings. These roofs provide excellent protection against harsh weather conditions, including high winds, heavy rain, and extreme temperatures. 

Metal roofing systems are available in a variety of materials, each offering distinct advantages depending on the building's needs and location. Their strength and resistance to weathering make them ideal for structures requiring long-term, low-maintenance solutions. Below are common materials used:

• Steel: Steel is one of the most widely used materials for metal roofs due to its strength, cost-effectiveness, and excellent corrosion resistance when coated with galvanization. Steel roofs are highly durable and can withstand severe weather conditions, making them a reliable choice for many commercial buildings.
  
• Aluminum: Aluminum is valued for its lightweight properties, making it easy to handle and install. It also has exceptional resistance to corrosion, particularly in coastal areas where saltwater exposure can deteriorate other metals. Aluminum roofs are ideal for buildings in humid or marine environments.
  
• Copper and Zinc: Copper and zinc are premium roofing materials known for their long lifespan and aesthetic qualities. Over time, these metals develop a natural patina, which adds a unique, weathered appearance while providing added protection against corrosion. These materials are often chosen for high-end commercial buildings and historical restorations.

Green Roofing Systems (Living Roofs)

Green roofs, also known as living roofs, offer a sustainable and eco-friendly alternative to traditional roofing systems by incorporating vegetation into the design. These roofs consist of a waterproof membrane with layers of soil and plants, allowing for the growth of a variety of vegetation. The popularity of green roofs is rising in commercial and urban environments due to their many environmental benefits.

They not only help improve building insulation and energy efficiency but also contribute to urban biodiversity, promote the reduction of stormwater runoff, and provide natural air purification. Green roofs are particularly beneficial in cities where green space is limited and where managing rainwater and reducing the urban heat island effect are priorities. Below are common materials used:

• Vegetation: Commonly used plants for green roofs include sedums, grasses, and other drought-resistant species. These plants are chosen for their ability to thrive in shallow soil and withstand varying weather conditions while providing greenery and aesthetic value.
  
• Waterproof Membrane: A durable waterproof membrane is critical to protect the building from water penetration, preventing damage to the structure beneath the roof.
  
• Drainage System: A well-designed drainage system ensures proper water flow, preventing water from accumulating on the roof. This system helps maintain healthy plants and protects the structure from excess moisture, which can lead to damage over time.

Built-Up Roofing (BUR) Systems

Built-Up Roofing (BUR) is one of the oldest and most dependable roofing systems, widely used for low-slope and flat commercial buildings. The BUR system consists of multiple layers of bitumen or asphalt, combined with reinforcing fabrics such as fiberglass or polyester. 

These layers are designed to provide an exceptional level of durability, waterproofing, and weather resistance, making BUR a reliable option for industrial, retail, and institutional buildings. Known for its longevity, a well-installed BUR system can last for decades with minimal maintenance, which is one of the reasons it remains a popular choice for flat or low-slope roofs. Below are common materials used:

• Asphalt or Bitumen: Bitumen or asphalt forms the base of the BUR system, offering flexibility and waterproofing capabilities. It is typically applied in several layers to ensure long-term protection against water infiltration.
  
• Reinforcing Fabrics: Fiberglass or polyester mats are embedded between layers of bitumen to increase the system's strength and durability. These fabrics enhance the roof's resistance to physical wear and tear and help prevent cracking.
  
• Gravel or Mineral Surfacing: To further protect the roof, a top layer of gravel or mineral surfacing is often applied. This layer shields the roof from UV rays, reduces weathering, and provides protection against foot traffic, making the roof safer for maintenance and inspection.

Single-Ply Membrane Roofing Systems

Single-ply membrane roofing systems have become a popular choice for commercial buildings, particularly those with low-slope or flat roofs. These modern roofing systems consist of a single layer of synthetic material that is applied directly to the roof deck.

Their simplicity, flexibility, and ease of installation make them highly efficient and cost-effective for both new construction projects and roof replacements. Single-ply membranes are known for their durability, resistance to harsh weather conditions, and energy efficiency, which makes them ideal for commercial applications. Below are common materials used:

• TPO (Thermoplastic Olefin): TPO is a highly energy-efficient material, known for its ability to reflect sunlight, which helps reduce cooling costs. It is also resistant to UV rays, chemicals, and ozone, making it an excellent choice for buildings in harsh environments.
  
• EPDM (Ethylene Propylene Diene Monomer): EPDM is a durable, black rubber membrane that offers excellent resistance to extreme temperatures and weathering. It is a reliable option for commercial buildings in regions with variable climates, providing long-lasting protection.
  
• PVC (Polyvinyl Chloride): PVC membranes are strong, fire-resistant, and resistant to punctures and chemicals. This material is perfect for areas with high foot traffic or exposure to harsh conditions, offering enhanced durability and safety for commercial spaces.

Shingle Roofing Systems

Shingle roofing systems are most commonly associated with residential buildings, but they can also be used in specific commercial applications, particularly for smaller buildings or those with a more residential appearance. These roofs consist of overlapping pieces of material installed from the bottom of the roof upward, forming a waterproof barrier that helps protect the structure from the elements. 

While shingle roofing is less common for large commercial buildings, it remains a practical option for smaller commercial properties, such as offices, retail shops, and low-rise buildings.Below are common materials used:

• Asphalt Shingles: Asphalt shingles are the most widely used type for both residential and light commercial buildings. Made from fiberglass or organic materials and coated with asphalt, they offer water resistance, durability, and an affordable price point.
  
• Wood Shingles or Shakes: Typically made from cedar, redwood, or pine, wood shingles provide a natural, rustic appearance. While durable, they require regular maintenance to prevent rot and pest infestations, especially in humid environments.
  
• Slate Shingles: Slate shingles are known for their durability, longevity, and aesthetic appeal. Though more expensive, they are ideal for commercial buildings seeking a unique, high-end look.
  
• Metal Shingles: Made from materials such as steel, aluminum, or copper, metal shingles are highly durable, fire-resistant, and provide a modern, sleek appearance.

Conclusion

Choosing the right commercial roofing system is vital for your building's longevity, energy efficiency, and maintenance. Each system offers unique benefits, whether you prioritize cost-effectiveness, sustainability, or durability. From easy-to-install flat and low-slope systems to energy-efficient metal and green roofs, there’s an option for every need.

While cost matters, it’s essential to consider long-term benefits such as energy savings, low maintenance, and resilience to local weather. By assessing your building’s requirements and consulting with roofing professionals, you can select the best option to protect your investment and enhance your business’s sustainability.