From "fire-baked" to "cold-applied" construction: Technological iterations of modified bitumen roofing membranes

In the field of building waterproofing, the development history of modified bitumen membranes is a history of technological evolution in construction methods, from "fire" to "cold," and from "complex" to "convenient." From the early "fire-baking" operations of traditional hot-melt materials such as SBS and APP, to today's "cold construction" processes of new bitumen-based materials such as self-adhesive and wet-laying, each technological iteration has profoundly responded to the industry's higher pursuit of safety, environmental protection, and construction efficiency. This article will systematically trace this technological evolution and showcase the innovative achievements of industry leader Canlon in this field.

I. The Era of Hot Melt Method: SBS/APP's "Bake-Up" Years

1. Origin and Development of Technology

SBS (styrene-butadiene-styrene block copolymer) and APP (atactic polypropylene) modified bitumen waterproofing membranes were the first generation of mainstream modified bitumen membrane products. In the 1980s, China imported related technologies and production lines from Europe, initiating the localization process of SBS/APP membrane production . These materials use fiberglass felt or polyester felt as the base and modified bitumen as the coating layer. Due to their excellent waterproofing performance and relatively economical cost, they quickly became the main product in China's building waterproofing market. Statistics show that in 2020, the output of SBS/APP modified bitumen membranes reached 758 million square meters, accounting for nearly half of the total output of waterproofing membranes.

2. Characteristics of the hot-melt construction method

Hot-melt application is the most common method for installing SBS/APP roofing membranes. Workers use a single or multi-head flame gun or blowtorch to heat the membrane's underside and the substrate. When the coating on the membrane's underside is heated until it turns black and glossy, it has nearly melted. At this point, rolling the membrane forward will allow it to bond to the substrate . Hot-melt membranes typically require a thickness of ≥3mm, and the application temperature should not be lower than -10℃ .

3. Limitations of the hot-melt method

However, the hot-melt method of construction has obvious safety and environmental hazards:

Fire risk : Using open flames during operations can easily lead to fire safety accidents.

Flue gas emissions : Harmful gases are released during the asphalt heating process, which affects the environment and the health of construction workers.

High requirements for the substrate : The substrate must be dry with a moisture content of less than 9%, and construction is subject to weather conditions.

Construction quality control is difficult : the flame temperature needs to be controlled between 200-250℃, which relies on the worker's experience and can easily lead to problems such as uneven adhesive layer and weak adhesion.

In recent years, with the tightening of safety and environmental protection policies, Beijing, Shanghai and other places have successively introduced regulations restricting the use of hot-melt construction methods , forcing the industry to seek safer and more environmentally friendly alternatives.

II. Innovation in Cold Construction: The Rise of Self-Adhesive and Wet Laying Technologies

1. The emergence of self-adhesive polymer-modified bitumen membrane

Self-adhesive polymer-modified bitumen waterproof membrane is a significant innovation addressing the limitations of the hot-melt method. This type of membrane is pre-coated with a self-adhesive layer at the factory; during on-site construction, simply remove the release liner and apply it directly to the substrate . Its core advantages include:

No-open-flame operation : Completely eliminates fire hazards and is suitable for construction sites where open flames are prohibited.

Easy to install : No complicated equipment required, faster installation speed.

Environmentally friendly and clean : No smoke emissions, friendly to the environment and human health.

Low temperature adaptability : Can be applied at lower temperatures and is not affected by humid environments.

2. Technological innovation in wet-laying method

The wet-lay method is a further evolution of self-adhesive technology. This process uses cement slurry as the bonding medium and can be applied before the substrate is completely dry. The membrane and substrate form a fully bonded structure through the hydration reaction of the cement slurry . The core value of the wet-lay method lies in:

Completely prevents water seepage : The waterproof layer adheres fully to the substrate, preventing water from spreading laterally even if there is local damage.

High tolerance for surface conditions : No need to wait for the surface to dry completely, which can shorten the construction period.

Reliable adhesion : The hydration reaction of cement grout forms chemical bonds, resulting in high bond strength.

3. Performance Upgrades of New Asphalt-Based Materials

By Canlon's MBA-CL and MBA-S series, have achieved a qualitative leap in material performance:

Excellent low-temperature flexibility : can withstand -29℃ without cracking , far exceeding traditional SBS roll materials.

High elongation: adaptable to substrate shrinkage, deformation and cracking.

Self-healing ability : It has excellent self-repairing properties against punctures and cracks.

Long-lasting adhesion : Forms a long-lasting and reliable seal with the substrate.

III. Comprehensive Comparison of Construction Methods

IV. Canlon: An Industry Leader in Cold Construction Technology

As a leading enterprise in China's building waterproofing industry, Canlon has profound technical expertise and a comprehensive product portfolio in the field of new bitumen-based waterproof membranes.

1. MBA Series Products

Canlon's MBA series self-adhesive rubber bitumen waterproof membrane is a core representative of its cold application technology :

MBA-CL : Using HDPE membrane as the top surface material, suitable for non-exposed roofs and underground projects.

MBA-S : With aluminum foil as the top surface material, it is suitable for exposed roofing applications.

The product thickness is available in various specifications, including 1.2mm, 1.5mm, and 2.0mm , to meet different engineering needs. Its technical performance has been certified by international authorities and has passed multiple certifications such as ISO, CE, and MSDS .

2. Core Technological Advantages

The superior performance of the Canlon MBA series products is reflected in :

Safe and environmentally friendly : The self-adhesive process enables solvent-free and flameless construction.

Excellent low-temperature performance : Flexible and crack-free at -29℃, suitable for extremely cold regions.

High elongation : Strong ability to adapt to base deformation.

Self-healing properties : It has the ability to self-repair punctures and micro-cracks.

Long-lasting seal : Forms a long-lasting and reliable bond with the substrate.

3. Continuous Innovation: Polyolefin Elastomer Film Self-Adhesive Membrane Sheet

Canlon has not stopped at its existing products, but continues to drive technological innovation. Its latest research and development, "Polyolefin Elastomer Membrane Single-Sided Self-Adhesive Bituminous Waterproof Membrane" (patent application number CN202320760605.5), uses TPO, POE and other polyolefin elastomer membranes to replace traditional HDPE membranes, achieving a comprehensive improvement in tensile properties, appearance flatness and overlap reliability .

This innovative product can be installed using self-adhesive or wet-lay methods, and the overlapping edges can simultaneously employ a combination of adhesive and welded overlaps, ensuring both sealing and improved overlap strength . This technological breakthrough opens up new possibilities for the future development of modified bitumen rolls.

V. Conclusion: Technological iteration never stops.

From the "fire-baking" era of SBS/APP to the "cold construction" revolution of self-adhesive/wet-laying, the technological iteration of modified bitumen membranes clearly outlines the direction of industry progress: safer, more environmentally friendly, more efficient, and more reliable. This evolution from "fire" to "cold" is not only a change in construction methods, but also a profound understanding of the essence of building waterproofing—a good waterproofing system should coexist and integrate with the building structure, rather than merely being an attached outer layer.

As an active participant and leader in this technological revolution, Canlon provides the market with time-tested waterproofing guarantees through its MBA series products and continuous innovation. Whether in underground projects, roofing systems, or special scenarios such as tunnels and swimming pools, Canlon products safeguard the safety and durability of buildings with their superior performance.

In the future, with the deepening of green building and "dual-carbon" goals, cold-applied construction technology will undoubtedly see broader application opportunities. Canlon will continue to be driven by technological innovation, contributing more "safer, more environmentally friendly, and more reliable" waterproofing solutions to the industry.