Resin for outdoor concrete

Outdoor concrete surfaces require proper protection to ensure they last for many years. Concrete resin is a material that not only protects concrete against damage, but also gives it an aesthetic appearance.

What is concrete resin?

Concrete resin is a specialized material used to protect and finish concrete surfaces. It is a synthetic substance based on polymers such as epoxies, polyurethanes or polyureas.

Why use concrete resin outdoors?

Outdoor concrete surfaces are exposed to weather conditions such as rain, snow, frost and UV radiation. The resin protects concrete against: 

• water ingress,
• scratches and mechanical damage, 
• cracking due to changing temperatures,
• dirt and stains, 
• various types of chemicals.

Additionally, the resin-coated surface looks modern and aesthetic, which undoubtedly increases the visual value of the investment and also affects the entire surrounding space.

Properties of the resin for external use

Resins used outdoors have a number of properties that make them an ideal choice: 

• Resistance to UV radiation - prevents the surface from yellowing and fading. The exception that does not have this property is epoxy resin, so it is not recommended to leave it outdoors without covering it with another, UV-resistant resin.
• Resistance to changing temperatures - polyurea and polyurethane resins are fully resistant to temperature changes, which in the Polish climate occur quite often both during the day and throughout the year. Coatings based on the above-mentioned resins do not crack or deform as a result of frost or heat.
• Waterproof - resin coatings for concrete protect it against moisture penetration, which prevents corrosion and mold growth. Additionally, water entering the pores of concrete and then increasing its volume, turning into ice during frosty days, may damage it. That is why it is so important to protect concrete, e.g. using resin preparations to extend its durability.
• Resistance to mechanical damage - resin materials perfectly cope with loads and intensive use. They come from industry, where they have often been subjected to all sorts of load tests. Therefore, they can also be successfully used in areas not entirely related to industry, such as parking lots, garages, driveways or ramps.
• Aesthetics - the ability to choose different colors and finishes (matte, gloss, anti-slip), as well as additives such as decorative flakes, liquid granite or colored quartz sand not only affect the proper protection of the floor. The obtained visual effect is pleasant for the user, which is an added value for the entire investment.

Types of resins for outdoor concrete

Depending on your needs and conditions, you can choose different types of resins:

Epoxy resin

Perfect for surfaces exposed to intense loads. It is characterized by high durability and chemical resistance, but may be less resistant to UV radiation. Therefore, for external applications, it is most often recommended to cover it with another type of resin, e.g. polyurethane, which is resistant to UV rays.

Polyurethane resin

More flexible than epoxy resin and resistant to changing temperatures. Perfect for outdoor applications where surfaces are exposed to sunlight. Most often, it is possible to dye this type of materials in any way, thanks to which it is possible to obtain any color on the vehicle, parking lot or ramp. Polyurethane resin is an excellent choice for protecting outdoor concrete in the period from late spring to early autumn, because it requires positive temperatures, most often around +10°C, for proper application.

Polyaspartic resin

Also known as polyurea resin, it creates a quick-drying and very durable surface. Suitable for places where quick work is necessary. Additionally, the entire investment using this type of materials can be performed at relatively low temperatures close to 0°. In such conditions, the polyurea resin hardens without any problems. It is worth remembering that polyurea coatings are also highly flexible, so they are perfect for various types of ramps, balconies and other outdoor places where the building or the ground perform some work.

Advantages of using concrete resin outdoors 

• Long service life – resin surfaces can be used for many years without the need for frequent repairs. Of course, it is worth periodically inspecting resin coatings to check whether there are any defects, deeper scratches or other damage as a result of use. Nevertheless, most often, resin floors on concrete last from several to a dozen or so years without the need for repairs.
• Aesthetic appearance – the ability to match the color and finish to the style of the surroundings. Creating colorful, interesting coatings using resins is usually very simple and has a strong impact on the perception of the entire environment. The use of decorative flakes and other additives is not an expensive procedure, but it gives a unique effect on a concrete floor.
• Resistance to weather conditions - an ideal solution for difficult weather conditions. Regardless of whether it is about protecting the concrete floor against moisture, temperature changes or UV rays, concrete resins can cope with all of them! When choosing a resin for outdoor use, it is worth considering polyurethane and polyurea resins.
• Anti-slip properties - resin floors on concrete can create a smooth and therefore slippery coating. It can be compared to smooth tiles. It is possible to easily eliminate this effect by using anti-slip additives, such as anti-slip microspheres for resins or quartz sand. Depending on wear, you can achieve an anti-slip effect from class R10 to even R13!
• Concrete protection - in addition to being resistant to weather conditions, concrete resins have excellent resistance to mechanical damage and chemicals. Therefore, the concrete floor is protected, for example, against abrasion. If it is known in advance that specialized chemicals are to be used in a given location, when selecting a concrete resin, it is worth checking the technical data sheets of resin manufacturers to choose the one with the best resistance to selected chemicals.

How to apply concrete resin outdoors?

The application of the resin requires proper preparation of the substrate, as well as several other steps for the entire process to be effective. The basic steps to take are:

• Surface preparation: The surface on which the resin is to be applied should be clean, free of grease, dust and dirt. If there are any, it is necessary to degrease the floor using e.g. concrete degreasers. Additionally, it is recommended to vacuum the floor every time before applying the resin on concrete, including outdoors, to remove dust particles and other contaminants that cannot be removed manually. At this stage, it is also necessary to fill in any defects in the concrete surface so that the final visual effect is satisfactory. It is also recommended to sand the concrete surface to increase the adhesion of the resin.
• Priming: In order to create adequate adhesion for the appropriate resin layer, it is recommended to prime the concrete first. In the case of outdoor concrete, there is never any certainty as to its moisture content deep inside. Most resin primers for concrete, which are based on epoxy resin, require 4% concrete humidity, which is difficult to achieve in the Polish climate, because there is high humidity for a significant part of the year and there is a relatively low number of sunny days. Therefore, an epoxy primer for wet concrete is recommended, e.g. Neopox Primer WS, which will not only create adequate adhesion for the resin, but also cope with the moisture trapped inside the concrete. A properly primed substrate should have the same shine. If any dull spots appear, this indicates increased absorbency of the substrate in a specific place and it is necessary to apply another layer of primer.
• Resin application: Apply the first layer of resin using a roller or trowel, depending on whether the product is thin or thick. After the first layer dries, further layers can be applied depending on the needs and type of product. When applying the resin outdoors, it is important to remember about the minimum humidity and temperatures of the air and substrate so that the application and subsequent hardening of the resin coating on concrete proceed properly.
• Finish: In some cases, it is worth using an additional surface layer, e.g. with anti-slip or protecting decorative flakes or liquid granite. For the floor to be fully functional, you must wait the appropriate time specified by the manufacturer in the technical data sheet of each product, which ranges from 24 hours to up to 7 days in the case of epoxies or polyurethanes.

Care and maintenance of outdoor resin surfaces

To ensure that the resin surface fulfills its function as long as possible: 

• It is worth cleaning it regularly to remove dirt using gentle detergents. 
• Avoid using aggressive chemicals that may damage the structure of the resin. 
• Check the condition of the coating - if you notice cracks or other damage, it is recommended to repair them quickly.

The most common outdoor resin problems

Although concrete resin is a permanent solution, some problems may occur:

• Cracks – resulting from improper preparation of the substrate or subsequent use.
• Yellowing – may occur with resins that are not sufficiently resistant to UV radiation, such as epoxy resins or aromatic polyurethanes.
• Mechanical damage – in case of very intensive use or the use of an inappropriate type of resin.
  To avoid problems, it is worth following the manufacturer's recommendations and using the services of professionals during application.