Versatile polyurea-based waterproofing membranes and protective coatings are an ideal solution for wood, metal, and concrete surfaces, which has made them gain popularity across a wide range of industries – in commercial, residential, healthcare, and mining sectors, among many others. Polyurea is used for protecting flat roofs, foundations, water containment and fuel storage systems, industrial and parking garage floors, industrial equipment, and much more. It can be applied by using four different methods, chosen based on project size and particular characteristics.
Polyurea and Its Types
What is polyurea?
To understand how polyurea can be beneficial for your project, it is important to know what this material is, along with its unique characteristics that make it stand out among other waterproofing coating options.
This durable material is a synthetic polymer obtained from a reaction between an isocyanate component (Part A) and an amine blend (Part B), also known as a resin. It can be applied to horizontal, vertical and curved surfaces, providing protection even for those buildings that have complex architectural structures. Depending on the isocyanate and resin formulation used, we can achieve the desired qualities, including hardness, elongation, dry/cure times, pigmentation, fire retardation, and moisture resistance, among others.
Aromatic vs Aliphatic
Depending on the project needs and budget, either an aromatic (non-UV) or an aliphatic (UV-resistant) polyurea can be chosen. The aromatic variety is less expensive but will not resist colour change however it willmaintain all of its properties when exposed to sunlight which makes it more appropriate either as a base coat, or for an indoor application (a warehouse floor, for instance). The aliphatic type on the other hand, withstands UV degradation – it is an optimal choice for exterior applications as a full system or as a top coat, giving the surface durable protection and a color stable glossy finish.
Polyurea and Its Many Benefits
Polyurea is an extremely versatile waterproofing membrane thanks to its many outstanding qualities, ranging from thermal stability to texture adjustment. Here are some of its many benefits:
- Ultra fast curing – it gels in five seconds, is tack-free in 15 seconds, and completely cured in 24 hours.
- Impressive chemical resistance – it protects surfaces against corrosive chemical fallout, acid rain, and salt.
- Exceptional mechanical properties – elongation, tensile strength, tear strength, and abrasion resistance. It will not become brittle.
- Thermally stable to temperature variations – a definite plus for the Canadian climate.
- Varied application temperature – it can be applied at temperatures ranging between 0°F to 150°F, with on a dry surface.
- Rapid application – large areas can be coated quicky with a spray-on application, making it a great choice for large industrial roofs or floors.
Versatile application – with adjustable thickness and textures, polyurea can be applied to horizontal, vertical and curved surfaces.
- Application thickness is relatively unlimited, which makes it possible to use polyurea not only as a coating but also as a crack filler and sealant – all in one go.
- Additional safety texture – while polyurea can have a smooth finish for a glossy, sliding result, a textured one is also available for slip resistance and safety (an optimal choice for pedestrian and vehicle traffic).
- A great choice for complex architectural features or roof applications with vent stacks, mechanical units, upturns, etc.
- A seamless and jointless application – the membrane will be effective due to the absence of cold joints.
- Environmentally friendly – polyurea’s solvent-free, 100% solids, no-VOC formula can be recycled fully into green composites. No outgassing occurs during the application process.
Polyurea and Its Application Methods
Currently four different application methods are available: high-pressure hot spray, warm spray coating, low-pressure cold spray, and roll-on or brush-on.
High-pressure hot spray
This method is ideal for projects of large size, such as commercial or industrial roofs, where significant areas must be coated quickly. The surface must be properly prepared, polyurea components must be mixed (a lower viscosity coating is used to ensure proper material flow during the application, to provide a uniform thickness). Spraying equipment used must be able to maintain temperatures up to 80°C (176°F) and pressure up to 210 bars.
Warm spray coating
Ideal for medium-size projects, this method uses a low-viscosity mix below 60°C (140°F).
Low-pressure cold spray
This is a method of choice for smaller waterproofing applications and areas that require repair.
Cola applied Polyurea must be brushed or rolled on in areas where spraying is not feasible – pipes, elevator pits, or high-rise building roofs, among others.
Polyurea and Its Many Uses
Polyurea-based membranes are an ideal solution for applications with high demands of protection against weather elements, as well as chemical, mechanical, abrasion, aging, and UV resistance. Such characteristics have made polyurea the material of choice for commercial, industrial, and high-rise residential roofing and flooring applications, among many others.
These membranes are also used in many other areas: as protective coatings in the mining sector and for bridges, wastewater treatment facilities, manhole / sewer linings, railway car and tank linings, pipe and pipeline coatings, marine applications, fuel storage and containment linings, tunnels, foundations, as coatings for commercial dumpsters and industrial equipment, water parks and swimming pools, and stadium seat coatings, among others.
Polyurea vs Others
Even though polyurea carries a higher price tag than epoxy, it is a much more superior coating in terms of UV, moisture, abrasion, chemical and temperature resistance. It is much more durable and cures a lot faster. When compared to polyurethane, polyurea is also much more lasting, with superior chemical and moisture resistance qualities.
Polyurea – Special Considerations
Because this material cures so fast and is highly reactive, the surface must be prepared adequately: without sufficient wetting, it will not adhere well to the substrate. For hot-spray applications, sophisticated (and expensive) equipment and highly trained applicators are needed. For exterior applications, aliphatic polyurea should be chosen, since it is UV-resistant and will not lose its qualities when exposed to sunlight.
Polyurea – a Great Option
Despite a possible drawback of a higher cost (depending on the nature of the project, it can be worthwhile, or might be the only option if lasting results are required), polyurea-based membranes are the optimal choice in most cases. Polyurea is a durable waterproofing solution capable of standing up to a variety of challenges.