The Rise of Single-Ply Roofing Systems: A Paradigm Shift from "Multi-Layer" to "Single-Ply"

In the field of building waterproofing, a profound conceptual transformation is reshaping the design and construction logic of roofing systems. Traditional "built-up roofing" adopts a "heavy" approach of stacking multiple layers of asphalt and felt, attempting to achieve waterproofing through material accumulation. In contrast, the "single-ply roofing system," represented by TPO and PVC membranes, achieves a fundamental shift from "quantity" to "quality" and from "layering" to "integration" with its lightweight yet multifunctional single-layer membrane.

Single-ply roofing refers to a roofing system that uses a single layer of flexible waterproofing membrane as the primary waterproofing component, working in conjunction with insulation layers, vapor retarders, and other components. Introduced to China in 1999, after more than two decades of development, it has become widely adopted in industrial plants, stadiums, airports, large commercial buildings, and other venues, emerging as a mainstream choice for modern roofing projects.

Part 1: From "Multi-Layer" to "Single-Ply": A Conceptual Revolution

Traditional roofing waterproofing largely relied on "built-up" designs, creating a waterproof barrier through multiple layers of asphalt and felt. This approach has significant drawbacks: numerous structural layers, high self-weight, long construction periods, and difficult maintenance. More critically, the interfaces between multiple layers are themselves potential leakage pathways.

Single-ply roofing systems subvert this logic. They integrate waterproofing, insulation, vapor retardation, and other functions into a concise system, achieving reliable waterproofing with just a single layer of high-performance membrane. This "subtractive" design philosophy brings a series of revolutionary advantages:

1. Significant Reduction in Building Load

Single-ply roofing systems are extremely lightweight, weighing only approximately 2-5 kg per square meter—far less than traditional built-up roofs (typically 15-30 kg/m²). This is of great significance for load-sensitive buildings such as large-span steel structures and light-gauge steel plants, as it not only reduces the cost of the primary structure but also reserves load capacity for subsequent photovoltaic installations.

2. Substantial Reduction in Construction Time

Using wide-width membranes in a single layer, combined with mechanical attachment or hot-air welding, construction efficiency improves by more than 30% compared to traditional processes. With fewer structural layers and no need to wait for layers to dry or cure, rapid continuous operations are achievable. This advantage is particularly pronounced for large projects with tight schedules.

3. Ease of Inspection and Repair

The single-layer structure means that leakage points are easier to locate and repairs are more convenient. When renovation is required, the old membrane can be completely removed and replaced without damaging the insulation layer. In built-up roofs, leaks are often difficult to pinpoint precisely, and repair costs are high.

Part 2: Core Attachment Methods: Mechanically Attached vs. Fully Adhered

The reliability of single-ply roofing systems depends significantly on how the membrane is secured to the substrate. The two mainstream methods are mechanically attached and fully adhered systems.

1. Mechanically Attached System

The mechanically attached method uses specialized screws with metal plates or battens to fasten the waterproofing membrane to the roof deck (concrete, steel, or wood). The fasteners are then covered by the membrane overlap and a complete waterproof layer is formed through hot-air welding.

The core advantages of this method include:

Excellent Wind Uplift Resistance: Evenly distributed attachment points resist high wind loads

Fast Installation: Unaffected by low temperatures or damp conditions, enabling year-round construction

Lower Overall Cost: No adhesives required, offering advantages in both material and labor costs

Mechanically attached systems are the most common installation method for single-ply roofing, particularly suitable for light-gauge steel roofs and large-span industrial plants.

2. Fully Adhered System

The fully adhered method uses specialized adhesives to bond the entire waterproofing membrane to the substrate surface, with overlaps also welded using hot air. This method is suitable for roofs with complex configurations and numerous penetrations, as well as concrete decks where mechanical fastening may be difficult.

Advantages of the fully adhered method include:

Smooth and Aesthetic Appearance: No exposed fasteners, providing better visual appeal

Excellent Wind Uplift Resistance: Full adhesion distributes wind loads evenly across the membrane

Flexible Detail Treatment: Reliable handling of irregular shapes, inside/outside corners, and other details

In recent years, the emergence of self-adhered single-ply membranes has further simplified fully adhered installation—the membrane underside is factory-coated with adhesive, requiring only release liner removal and direct application, eliminating on-site adhesive application and significantly improving installation efficiency.

3. Hot-Air Welding: The Ultimate Assurance for Seams

Regardless of whether mechanically attached or fully adhered, TPO/PVC membrane overlaps are joined using hot-air welding. High-temperature hot air causes the polymer molecular chains to mutually penetrate and entangle, forming welds with strength exceeding that of the parent material. This "homogeneous welding" technology ensures the integrity and durability of the waterproofing layer and is the core technical assurance for achieving "zero leakage" in single-ply roofing systems.

Part 3: Application Scenarios: From Industrial Plants to Large Public Buildings

Leveraging its lightweight, efficient, and reliable characteristics, single-ply roofing systems have achieved continuously increasing adoption rates in the following scenarios:

Industrial Plants & Logistics Warehouses: Light-gauge steel structures are sensitive to load, and the lightweight advantage of single-ply roofing is a perfect match. Additionally, large, regular roof areas allow the efficiency advantages of mechanical attachment to be fully realized.

Stadiums & Convention Centers: Large-span spatial structures require lightweight yet strong roofing materials. The hot-air welding technology of single-ply membranes creates seamless waterproofing layers that adapt to complex curved geometries.

Airports & Transportation Hubs: These facilities demand extremely high waterproofing reliability and cannot be taken out of service for extended periods. The fast installation and easy repair characteristics of single-ply systems meet these requirements precisely.

Commercial Buildings & Data Centers: Waterproofing failure can result in enormous economic losses. The extended durability and inspectability of single-ply systems provide reliable protection for asset safety.

According to statistics, China's single-ply roofing market reached 8.489 billion yuan in 2025. Globally, the single-ply membrane roofing market was valued at USD 5.25 billion in 2024 and is projected to reach USD 14.33 billion by 2033, growing at a CAGR of 11.8%. North America and Asia-Pacific are the two fastest-growing markets.

Part 4: Canlon: China's Power in Single-Ply Roofing Systems

As a leading enterprise in China's building waterproofing industry, Canlon has established a comprehensive product portfolio and technical capabilities in the field of single-ply roofing systems.

1. Full Range of Polymer Membranes

Canlon's high-performance TPO and PVC waterproofing membranes are manufactured on imported custom production lines, excelling in weatherability, UV resistance, and long-term durability. White TPO membranes achieve reflectivity exceeding 85%, effectively reducing building energy consumption and making them an ideal choice for green roofs and photovoltaic roofs.

2. Systematic Solutions

Canlon provides end-to-end services covering material supply, system design, and construction guidance. For different building types and site conditions, either mechanically attached or fully adhered methods can be flexibly selected to ensure optimal waterproofing protection for each project.

3. Deep Integration with Photovoltaic Roofs

Canlon has jointly developed an integrated commercial and industrial photovoltaic roofing system with GoodWe, using high-performance TPO membranes as the waterproofing substrate deeply integrated with photovoltaic building materials, achieving system capability where "PV and roof share the same lifespan". Canlon New Energy has consecutively won the "BIPV Technology Leadership Award," demonstrating its leading strength in the photovoltaic roofing sector.

4. Landmark Project Validation

Canlon's polymer waterproofing systems have been successfully applied in landmark projects both domestically and internationally, including Beijing Daxing International Airport, China Zun, Suzhou Jinji Lake Tunnel, and Roche Tower in Switzerland, earning market trust through "leak-free" excellent performance.

Part 5: Conclusion: The Era of Single-Ply Roofing Has Arrived

The transition from "multi-layer" to "single-ply" is not merely a simplification of construction processes but a fundamental leap in roofing design philosophy. With its significant advantages of lightweight efficiency, fast installation, and easy maintenance, the single-ply roofing system is redefining the standards of modern building roofing engineering.

Polymer membranes represented by TPO and PVC, through the perfect combination of mechanical attachment and hot-air welding technology, achieve synergistic integration between the waterproofing layer and the building structure, providing reliable protection for 25-30 years. This technical path not only aligns with the contemporary requirements of green building and "Dual Carbon" goals but also provides a solid technical foundation for emerging applications such as building-integrated photovoltaics.

As a Chinese force in this field, Canlon is promoting the widespread application of single-ply roofing systems both in China and globally through continuous technological innovation and excellent product quality, contributing core value to building safety and sustainable development.