What is the Most Common Type for Commercial Roofing? A Complete Guide

When it comes to commercial roofing, choosing the right system can significantly impact your building's performance, maintenance costs, and longevity. Understanding the most common commercial roofing types — and their respective advantages — is essential for making an informed decision that protects your investment for decades to come.

The Most Common Commercial Roofing Types

Commercial roofs differ significantly from residential roofs due to their larger surface areas, lower slopes, and higher performance demands. Here are the most widely used commercial roofing systems in Australia today:

1. Metal Roofing (Most Popular in Australia)

Market share: Metal roofing accounts for approximately 60-70% of commercial roofing installations in Australia, making it by far the most common choice for businesses, warehouses, industrial facilities, and retail centers.

Why Metal Roofing Dominates the Commercial Market:

• Exceptional durability: 40-70 year lifespan with minimal maintenance
• Fire resistance: Non-combustible materials provide superior fire protection
• Weather resistance: Performs exceptionally well in Australia's harsh sun, wind, and rain
• Energy efficiency: Reflective coatings reduce cooling costs by 20-30%
• Cost-effectiveness: Lower lifecycle costs compared to most alternatives
• Fast installation: Large sheets mean quicker installation, reducing labor costs
• Lightweight: Minimal structural load compared to concrete or tile

Common Metal Roofing Materials:

Best Applications for Metal Roofing:

• Warehouses and distribution centers
• Manufacturing facilities
• Retail shopping centers
• Office buildings
• Agricultural buildings
• Sports facilities and arenas

2. TPO (Thermoplastic Polyolefin) Membrane Roofing

Market share: TPO accounts for approximately 15-20% of commercial roofing installations in Australia, particularly popular for flat or low-slope applications.

Key Features of TPO Roofing:

• Heat-welded seams: Creates a watertight monolithic membrane
• UV resistance: White surface reflects sunlight, reducing cooling costs
• Flexibility: Accommodates building movement without cracking
• Chemical resistance: Resistant to oils, fats, and bacterial growth
• Lifespan: 20-30 years with proper maintenance
• Cost: $60-$95 per m² installed

Best Applications for TPO:

• Flat roof commercial buildings
• Restaurants and food processing facilities
• Healthcare facilities
• Buildings with HVAC equipment on the roof

3. EPDM (Rubber) Membrane Roofing

Market share: EPDM represents about 10-15% of commercial roofing installations, favored for its proven reliability and cost-effectiveness.

Advantages of EPDM Roofing:

• Exceptional durability: Highly resistant to UV radiation and ozone
• Temperature tolerance: Performs well in extreme heat and cold
• Low maintenance: Minimal upkeep requirements
• Easy repairs: Patches and repairs are straightforward
• Lifespan: 25-35 years
• Cost: $50-$80 per m² installed

Limitations to Consider:

• Black color absorbs heat (though white versions are available)
• Vulnerable to punctures from sharp objects
• Seams can fail if not properly installed or maintained

4. Built-Up Roofing (BUR)

Market share: Once the dominant commercial roofing type, BUR now accounts for approximately 5-10% of new installations but remains common on existing buildings.

What is Built-Up Roofing?

BUR consists of alternating layers of reinforcing fabric (felt) and bitumen (asphalt or coal tar), topped with a layer of gravel or a reflective coating. This creates a multi-layered, redundant waterproofing system.

Characteristics:

• Proven track record: Technology with over 100 years of use
• Redundancy: Multiple layers provide backup waterproofing
• Fire resistance: Gravel surface offers excellent fire protection
• Heavy weight: Requires strong structural support
• Lifespan: 20-30 years
• Cost: $55-$90 per m² installed

5. Modified Bitumen Roofing

Market share: Modified bitumen accounts for approximately 5-8% of commercial installations, primarily on smaller commercial buildings.

Key Features:

• Hybrid technology: Combines traditional built-up roofing with modern polymer modifications
• Flexibility: APP or SBS polymers provide enhanced flexibility and durability
• Installation methods: Torch-applied, cold-applied, or self-adhering
• Lifespan: 15-25 years
• Cost: $50-$85 per m² installed

Comparing the Most Common Commercial Roofing Types

Why Metal Roofing is the Top Choice for Australian Commercial Buildings

Metal roofing's dominance in the Australian commercial market isn't accidental. Several factors make it particularly well-suited to Australian conditions and commercial requirements:

1. Climate Suitability

Australia's harsh sun, high UV radiation, and extreme weather events favor metal roofing's superior durability and reflectivity. Metal roofs withstand intense heat, heavy rain, and high winds better than most membrane systems.

2. Lifecycle Cost Advantage

While initial costs may be higher than some membrane systems, metal roofing's 40-70 year lifespan and minimal maintenance requirements result in the lowest total cost of ownership over the building's life.

3. Sustainability

Metal roofing is 100% recyclable at end of life, often contains recycled content, and its reflective properties reduce energy consumption — making it the most environmentally responsible choice.

4. Building Code Compliance

Metal roofing easily meets Australian building codes for fire resistance, wind rating, and structural performance, particularly in bushfire-prone areas.

How to Choose the Right Commercial Roofing Type

Selecting the best roofing system for your commercial building depends on several critical factors:

1. Building Use and Occupancy

• Warehouses and industrial: Metal roofing excels due to durability and large-span capability
• Restaurants and food service: TPO offers chemical resistance and easy cleaning
• Office buildings: Standing seam metal provides aesthetics and performance
• Healthcare facilities: TPO or EPDM for flat roof applications with HVAC equipment

2. Roof Slope

• Flat to low-slope (0-3°): TPO, EPDM, built-up, or standing seam metal
• Low-slope (3-10°): Metal roofing or modified bitumen
• Moderate to steep slope (10°+): Metal roofing is typically the best choice

3. Budget Considerations

• Lowest upfront cost: EPDM or basic modified bitumen
• Best long-term value: Metal roofing (lowest lifecycle cost)
• Mid-range balance: TPO membrane or Colorbond metal

4. Climate and Environmental Factors

• High UV exposure: Metal roofing or white TPO/EPDM
• Bushfire zones: Metal roofing (BAL-rated systems available)
• Coastal environments: Colorbond or marine-grade metal systems
• Extreme temperatures: Metal roofing handles thermal cycling best

5. Maintenance Capacity

• Minimal maintenance staff: Metal roofing requires least upkeep
• Regular maintenance available: Any system can perform well
• Deferred maintenance likely: Choose most durable option (metal roofing)

Future Trends in Commercial Roofing

The commercial roofing industry continues to evolve with new technologies and environmental priorities:

Emerging Trends:

• Cool roof technology: Highly reflective coatings reducing urban heat island effect
• Solar integration: Metal roofs with integrated solar panel systems
• Green roofing: Vegetation systems, primarily on membrane roofs
• Smart roof sensors: Monitoring systems detecting leaks and damage early
• Sustainable materials: Increased recycled content and recyclability
• Improved warranties: 30-50 year manufacturer warranties becoming standard

Conclusion

Metal roofing stands as the most common commercial roofing type in Australia for compelling reasons: exceptional durability, low maintenance, superior weather resistance, and the best long-term value. While membrane systems like TPO and EPDM have their place — particularly on flat roofs or specialized applications — metal roofing's 40-70 year lifespan and minimal upkeep make it the preferred choice for the majority of commercial buildings.

When selecting a commercial roofing system, consider your building's specific requirements, budget constraints, and long-term maintenance capabilities. In most cases, investing in quality metal roofing delivers the best return on investment and peace of mind for decades to come.