Flexible waterproofing solutions for versatile and durable protection

Creating coatings for multiple waterproofing applications

Modern construction requires waterproofing solutions that perform reliably across various surfaces, such as roofs, terraces, balconies, parking decks, basements, or structures in contact with soil.

Solutions from Covestro support high-performance waterproofing in these environments by offering a wide array of technical properties, including flexibility, durable crack-bridging, temperature resistance, abrasion resistance, and stable water vapor transmission.

To address both conventional and emerging needs, we offer a broad and flexible portfolio, including isocyanate monomers, polyols, prepolymers, polyurethane dispersions, and intermediates that are ready for formulation. 

Polyurethane is the dominant high-quality waterproofing technology, particularly in Europe. It offers an excellent balance of flexibility, crack-bridging capability, adhesion, and long-term durability. As one of the pioneers of polyurethane technology, we are a long-standing partner to many leading waterproofing producers worldwide, helping to shape durable, high-quality waterproofing systems used across the construction industry.

We support polyurethane waterproofing with aromatic and aliphatic prepolymers, isocyanate monomers and polyether polyols for captive production, and polyurethane dispersions for water-based systems and hybrid formulations.

1K polyurethane systems are widely used for roofing, balconies, terraces, basements, podium decks, and other applications that require high water resistance. They cure through the reaction of their isocyanate component with moisture, and can be applied by roller or brush. This makes them well suited to standard construction workflows. Ease of application and reliable performance make 1K PU membranes the workhorse of modern waterproofing. Desmodur® aromatic prepolymers allow coating manufacturers to incorporate crack bridging and elasticity into coatings, making them suitable for environments with frequent substrate movement. 

Desmodur® aromatic prepolymers can also be used to create 2K polyurethane systems. 2K systems often provide higher mechanical strength and controlled curing, making them suitable for more demanding applications such as car parks, industrial flooring, and high-traffic surfaces, where quick return to service after repairs is required.

We also supply aliphatic polyisocyanates for both PU and polyurea systems, which provide UV stability, color retention, and weathering resistance – essential for exposed top layers. These hardeners enable coatings manufacturers to produce exterior waterproofing solutions with lasting resistance to sunlight and harsh weather conditions.

Additionally, we offer polyurethane dispersions (PUDs) such as Bayhydrol® for water-based waterproofing solutions. These dispersions significantly enhance mechanical properties of acrylic coatings, providing improved tensile strength and flexibility at low temperatures. The benefits include enhanced toughness, better dirt pick-up resistance, low-viscosity application, quick drying, and simple water-based cleanup. This makes them particularly suitable for both roofing and flooring systems where environmental considerations are important.

Combining Bayhydrol® with polyisocyanate hardeners like Bayhydur® can enhance performance in water-based waterproofing and roof-coating systems.

Polyurea systems represent a fast-growing segment in high-performance waterproofing, especially where speed and durability are critical.

These 2K spray-applied systems cure within minutes and allow a fast return to service. Polyurea coatings offer very high tensile strength and elongation, making them suitable for demanding environments such as car parks, bridges, large roofs, industrial structures, and infrastructure projects.

The high performance of polyurea comes with specific requirements: application typically involves heated, high-pressure spray equipment and trained applicators. As a result, polyurea is often selected for specialized projects where fast installation and outstanding mechanical performance outweigh higher material and application costs.

We supply key raw materials and prepolymers for polyurea systems, including Desmodur®, supporting both integrated producers and specialized polyurea applicators.

In addition to spray-applied polyurea, fast-curing polyaspartic systems offer light-stable, high-quality solutions that can be applied by roller or brush for selected waterproofing and decorative flooring applications.

No single waterproofing technology fits every project. The right choice depends on performance requirements, application conditions, available time, and cost considerations; the highest-performing waterproofing systems are not always the easiest to apply. 

For less demanding waterproofing applications, water-based acrylic coatings are often chosen for their low cost and ease of use. However, these systems offer limited durability compared with polyurethane or polyurea membranes.

To improve performance, many manufacturers use polyurethane-modified acrylic systems. The polyurethane dispersions in these systems enhance flexibility, especially at low temperatures, ponding water resistance, and mechanical properties. The portfolio of polyurethane dispersions we offer supports such hybrid approaches.