The technical advantages of HDPE (MBP) pre-applied reverse bonding method – an engineering revolution in polymer waterproof membranes.

In the field of underground waterproofing engineering, "water seepage" has been a persistent problem that has plagued the industry for decades. In traditional waterproofing methods, the waterproofing layer and the structural layer are separate. Once the waterproofing layer is partially damaged, groundwater can seep long distances along the gaps between the two, penetrating into the interior through weak points in the building structure, and the leakage point is extremely difficult to pinpoint. HDPE polymer self-adhesive pre-applied waterproof membrane and its matching pre-applied reverse-adhesive method are revolutionary solutions to this problem. This article will focus on Canlon's MBP-P and MBP-Pro series products to deeply analyze the core advantages and engineering value of this technology.

I. Pre-applied reverse bonding method: A fundamental shift from "isolation" to "fusion"

Pre-applied reverse bonding is a revolutionary construction technique. Traditional waterproof membranes are laid on the base layer using the "full bonding method" or "loose laying method," and there is always a physical interface between the waterproof layer and the subsequent poured main structure. In contrast, the pre-applied reverse bonding method lays the membrane on the subbase or enclosure structure in advance, and pours concrete directly facing the bottom slab reinforcement, so that the waterproof layer and the main building structure can achieve permanent full bonding and fusion .

The core material of this process is a self-adhesive polymer waterproof membrane with HDPE (high-density polyethylene) as the base material. Its technological advantages can be summarized in the following four aspects:

1. "Skin-like" waterproofing completely eliminates water seepage channels.

The essence of the pre-applied reverse bonding method is to transform the waterproofing layer into the "skin" of the building structure. When the un-set cement slurry in the subsequently poured concrete comes into contact with the polymer self-adhesive film on the surface of the membrane under pressure, the two undergo creep interpenetration , forming a molecular-level physical anchoring and chemical bond . After the concrete has cured, there are zero gaps and no interface between the membrane and the main structure. Even if groundwater penetrates a point in the waterproofing layer, it cannot spread laterally, and the risk of leakage is strictly locked within a very small area.

2. It has extremely high adaptability to construction and remains reliable even under harsh working conditions.

HDPE rolls possess excellent mechanical properties and chemical resistance, while the pre-applied reverse-adhesive process further reduces the requirements for substrate conditions. No leveling layer, open flame operation, or weather waiting is needed. Even in extreme environments such as underwater, rainy days, low temperatures, and condensation, the MBP-Pro rolls with their "adhesive-bonded" overlap design can still achieve reliable overlaps . The successful application in the 28-meter-deep water-permeable environment of Jinan Metro Line 6 is the ultimate proof of this advantage.

3. The construction period is significantly shortened, resulting in a substantial overall cost advantage.

The pre-applied reverse bonding method eliminates the need for a protective layer. After the membrane is laid, steel bars can be tied and concrete poured directly, simplifying the process and reducing overlapping operations. At the same time, the membrane has a wider width and fewer overlaps, improving construction efficiency by more than 30% compared to traditional methods.

4. Green and environmentally friendly, in line with the direction of sustainable development.

The cold construction process is solvent-free, flameless, and produces no smoke emissions. HDPE material itself is non-toxic, harmless, and recyclable. MBP-P rolls have been included in the National Green Building Materials Accreditation and Application Database , becoming a priority choice for government-invested projects and green buildings.

II. Canlon MBP Series: A Technological Leap from "Domestic Leading" to "International Quality"

As the first listed company on the ChiNext board in China's building waterproofing industry, Canlon has been deeply involved in the field of polymer waterproofing for more than ten years. Its MBP (Migration Barrier Product) series of polymer self-adhesive pre-applied waterproof membranes has become the technical benchmark and sales champion in this category in China.

1. Product portfolio: A dual-flagship strategy with MBP-P and MBP-Pro

MBP-P High-Polymer Self-Adhesive Pre-Layer Waterproofing Membrane : Composed of high-density polyethylene (HDPE) sheets, a high-polymer self-adhesive membrane, and a granular anti-adhesive layer. It achieves fusion waterproofing with the concrete structure through interpenetration bonding between the adhesive and cement slurry . This product has obtained EU CE certification and has been widely used in landmark projects both domestically and internationally, such as the China Zun and the Roche Swiss Headquarters Building.

MBP-Pro polymer self-adhesive pre-applied waterproof membrane : This membrane represents an extreme enhancement of the application performance of the MBP-P membrane. Its core breakthrough lies in its underwater overlapping capability —the long edges of the membrane feature an adhesive-backed overlap design, with a back-coated overlap edge on the underside. Even in extreme environments such as underwater, rain, and low temperatures, the overlap strength remains stable and reliable . The white virgin material sheet ensures no recycled materials are mixed in, guaranteeing pure and traceable quality.

2. Technical parameters and performance advantages

Dimensional stability : The dimensional change rate of the roll material does not exceed 5/1000, which is far superior to similar products in the national standard. It is not easy to bulge or wrinkle under sun exposure.

Weather resistance : The specially formulated polymer self-adhesive film and granular anti-adhesive layer enable the roll material to retain its pre-applied anti-adhesive properties after more than 49 days of on-site trampling, sun exposure and rain.

Corrosion resistance : Passed the "acid, alkali and salt" chemical resistance test of the National Building Materials Testing Center, suitable for complex geological environments.

3. Benchmark Project: Flawless from China to the World

Domestic benchmarks : The Zhengzhou Zhengfa Building project won the 2022-2023 Luban Award for Construction Engineering in China, and its foundation slab waterproofing uses Canlon MBP pre-applied membrane ; the underground integrated pipe gallery in Songjiang South New City, Shanghai was selected as a science and technology demonstration project by the Ministry of Housing and Urban-Rural Development, and MBP membranes provided waterproofing protection with a 100-year design life ; the indoor waterproofing project of Beijing China Zun also selected Canlon products.

International Breakthrough : The Roche Tower in Switzerland —the tallest building in Switzerland—selected MBP-Pro waterproofing membrane for the foundation slabs of its 2nd and 3rd towers. Competing against top European brands, MBP-Pro successfully won the bid, demonstrating its competitiveness of "international quality at Chinese prices . " MBP-Pro has also been applied in dozens of projects in major commercial projects in San Jose, California , as well as in Los Angeles, San Francisco, and Chicago.

Extreme working conditions : In the water-permeable environment 28 meters underground of Jinan Metro Line 6 , the MBP-Pro was tasked with replacing the original failed solution, completing 50,000 square meters of underwater construction and successfully passing the acceptance test. It was hailed by the customer as "a good solution to the problem of waterproofing in subway tunnels".

III. Conclusion: Pre-applied reverse bonding defines the future of underground waterproofing.

HDPE pre-applied reverse bonding is not a repair of traditional processes, but a fundamental reconstruction of the logic of underground waterproofing. It transforms the waterproof layer from an "outer garment" into a "skin," and from "isolation" to "integration." Along this technological path, Canlon has built a complete product portfolio with its MBP-P and MBP-Pro models, covering standard applications to extreme conditions. Backed by national green building material certifications, international engineering recognition, and the Luban Prize, Canlon has established its leading position in the HDPE pre-applied waterproofing field.

Choosing pre-applied reverse bonding means choosing a waterproofing system that coexists with the structure; choosing Canlon MBP means choosing reliable protection proven by top global engineering projects.