
Cork spray is typically a kind of coating that combines cork (the outer bark of the cork oak tree (Quercus suber L.) and water resin to create a layer of thermal insulation.
The good part is you can apply cork sprays over most surfaces. Its versatility has helped to make it a popular choice for those who cover the exterior of homes.
If you are wondering whether cork spray rendering suits your building or property, you need to understand its benefits over other coatings, along with some drawbacks. So, let’s dive into them right here…
Cork Spray Advantages
Cork spray is becoming more popular, with contractors and homeowners finding advantages in this product.
It’s not only suitable for coating buildings and structures but also great for pool decks. Walking on the cork-coated surface with bare feet is comfortable because it absorbs heat. Moreover, you can choose any color for the cork spray, making the deck more aesthetically pleasing.
a) Sustainable and Eco-friendly
One of the most important benefits is that cork is an eco-friendly, sustainable resource that regrows every time it’s stripped off the tree. Also, the harvesting process doesn’t harm the tree, and it actually helps to release oxygen into the air and reduces carbon dioxide in the environment.
b) Thermal Insulation
If you want to cut down on heating bills, then using cork spray is an excellent answer. You can use it just like paint to cover the surface, and it will act as a shield against heat coming into or leaving the structure. This means less temperature variation during the summer and winter months, keeping your AC or furnace from working overtime.
c) Fire-retardant and Sound Reduction
Another benefit of cork rendering is that it’s a fire-retardant substance. Because the mixture of cork to water resin is relatively high in the spray, the fire-retardant capabilities are pretty strong, which helps to make the structure more resistant to fire that either starts or spreads to the outside of the building or home.
Furthermore, cork spray also has great soundproofing abilities so that noise is reduced from the outside as well as the inside. Acoustic improvement because of cork also minimizes impact sound and keeps the structure from vibrating when there are disturbances, like high winds.
d) Better than Paint
Although cork spray is often used on exterior surfaces, it is also suitable for interior use. In fact, it can be applied to any surface where traditional paint can be used, including brick, stucco, vinyl, and wood.
The cork’s elasticity allows it to breathe with the surface, maintaining its integrity over time without peeling or cracking. This means it lasts longer than paint that may peel, crack, or flake in sunlight. Additionally, cork spray can be customized to match any color, not just natural cork or brown, which can enhance the appearance of your building.
e) Mold, Mildew, and Water
One of the most damaging elements for our home is water. Whether in the form of rain, hail, sleet, snow, or flooding, it can cause significant damage to the exterior surfaces of your residence or business place.
Water is also a critical element in the growth of mold and mildew. Without it, neither substance will do much to your home.
Because cork is hydrophobic, it makes it quite difficult for moisture to penetrate through facades, roofs, ceilings, and floors. This means adding a layer of cork spray prevents the mold and mildew from coming into contact with the water it needs to continue growing.
Also, when you add cork spray to the interior of your building, you compound the water resistance to make it even more beneficial.

Cork Spray Disadvantages
Despite its beneficial properties, the projected cork rendering on homes presents some issues. These include:
a) Quality and Higher Cost
The primary downside of sprayed cork is that it is highly dependent on the quality of its application. If the material is not treated and applied correctly, it may lose its water-repelling ability and become vulnerable to leaks and humidity on both facades and floors. Therefore, it is essential to ensure that sprayed cork is always high quality (like CorkSol) to avoid potential issues.
Of course, this also means that cork spray is often more expensive than traditional paint or other forms of home insulation, so it’s essential to consider the cost per square foot before deciding to use it. Calculating the energy or insulation savings will also help determine if the investment is worthwhile or not.
b) The Required Maintenance
In addition, cork spray will require proper maintenance over time (or even replacement) to keep its protective and insulation properties in place. This includes regularly cleaning the surface and trying to keep dirt, debris, and other substances from building up on it.
Also, since the protective properties of the spray get weaker with time, it’s essential to keep up with the maintenance in terms of sanding and repairs of hairline cracks, which will help maintain its water-resistance capabilities and keep the surface looking great for longer.
c) Not advisable to use in areas exposed to light
One significant drawback of sprayed cork is that it is not advisable to use it in areas that receive direct sunlight. This is because prolonged exposure to UV light can cause the cork to dry out and lose some of its properties, including the ones that make spray cork insulation waterproof. So, whenever possible, it is best to look for alternatives in these situations.
Also, keep in mind since spray cork is a liquid material that is applied with an airless sprayer, it can require special expertise to use in areas with irregular shapes. This can cause difficulties in the application process and make it harder to achieve a uniform finish. So, whenever possible, it is best to look for alternatives in these situations and consult with a professional to make sure the project is completed correctly.
Cork Coating – Usage, Tips & Cost
You may wonder if the cork spray is challenging to apply to the exterior of a building. The truth is that cork spray applies to the surface roughly the same way as stucco without needing a base layer. That said, it’s not advisable to spray cork yourself – it’s not for DIYers.
To use cork spray for your home or business and ensure a proper application process, it’s important to contact a licensed dealer to hire a professional applicator who will guarantee that the coating performs well and meets your expectations.
Once it has been professionally applied, it will provide a robust thermal shield that will last for quite some time while being quite flexible and resisting cracking.
How Much Does Cork Spray Render Cost?
The cost of materials used in work spraying can range between $2 and $5 per square foot. However, getting a fixed cost estimate associated with cork spray rendering is difficult without a professional inspecting your building first.
Since each property will require a unique approach, the price can vary depending on various factors, including:
- The quality of materials used
- Whether your building is single or multistories
- The dimensions of the area that requires cork spray
- The presence of ductwork that needs coverage with cork spray
- The need to apply cork spray on the roof and the slope of your roof (e.g., flat or not)
- Whether you are planning to sell your home or want to self-use after rendering
Cork spray is usually added to buildings after they have been completed. You can still use cork spray to improve insulation and protection if you have an older home. However, it’s essential to use high-quality products, take all necessary precautions and hire a professional contractor to ensure the job is done correctly.
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Jack Luis is a semi-retired painter who loved painting his clients’ ideas on their walls.
He had worked as a painter for over a decade serving customers in areas such as Charleston, Mount Pleasant, Beaufort, and Georgetown, SC (South Carolina). Today in his free time, he likes to read and write about the newer techniques implemented in his profession. You may read more about him here or get in touch with him here.