Polyurea has been around for decades and has numerous uses both in the industrial and commercial sector. One area polyurea is commonly used is in building and construction. Polyurea is especially popular in roofing systems where it can be sprayed on to provide a protective coating. When polyurea coating is sprayed onto the roof it can be applied in layers or applied in one thin coat. If more coats of polyurea coating are needed to achieve a desired protective coating, the layers can be added as needed.
When polyurea is sprayed onto substrates they are normally saturated with polyurea so that the chemical reaction that occurs when polyurea reacts with the substrate can take place. When polyurea is used on bare substrates nearly fully saturated with water polyurea won’t cause blistering nor does blistering happen when the air has high levels of moisture. Even in extremely low temperatures (as low as -40 deg C) polyurea coating still will cure. Once cured polyurea begins a chemical reaction which changes the substrate into a gel and causes a hardening process.
When polyurea coating is sprayed onto an surface they undergo a mixing and preparation process. During the mixing and preparation process a thin film of polyurea solution is applied onto the surface to be protected. The polyurea solution acts like a barrier keeping the contaminates out of the surface during the mixing and preparation process. This makes the surface preparation much easier because the mixing and preparation of the material does not create any contaminants and the contaminates have a higher chance of entering the surface than the other ingredients used during the coating process.
After the polyurea coating has been applied the application conditions need to be right for the coating to perform its job properly. Applying polyurea coating to concrete surfaces with the wrong application conditions can actually interfere with the performance of the coating. The most common application conditions for polyurea coating are:
Polyurea spray coatings can be used on concrete surfaces that have mild to moderate hydrostatic pressure, as well as concrete systems with heavy hydrostatic pressure. The polyurea coating can also be applied to concrete surfaces with cracks, hollow areas or those with unsightly voids. For concrete systems with significant cracks the polyurea spray coatings can also be used. To apply polyurea spray coatings the application conditions include: very good humidity, a fixed moisture content of 10 % or less, and an effective drying time. Polyurea spray coating can also be used on metal surfaces such as laminates and stainless steel. To apply polyurea spray coatings for metal surfaces, the application conditions include: very good humidity, a fixed moisture content of 10 % or less, and an effective drying time.
There are many more application conditions that can be used for polyurea coatings and coating concrete systems. They can even be applied on non-concrete materials such as steel and wooden lintels. However, the polyurea coatings with the highest level of resistance to moisture and thermal shock are the most commonly used polyurea coatings. They offer superior protection and long term stability against wear and tear, and they increase the aesthetic appeal of the building or structure.