Cool roofing is a technique aimed at reducing the amount of heat absorbed by a building’s roof by using reflective coatings (which reflect a large portion of solar radiation) to cover the roof in white.
This reduces the roof’s surface temperature and significantly limits heat flow into the building.
This technique can be implemented using a variety of materials and can lead to reduced energy consumption for air conditioning and a higher level of thermal comfort.
Cool roofing can significantly reduce the temperature inside buildings, reducing reliance on air conditioning and lowering energy costs. It also helps combat urban heat islands.
These benefits demonstrate the effectiveness and added value of CoolRoof coating, particularly in terms of durability, energy savings and environmental protection.
The Cool Roof solution is also available internationally. We are present on two continents thanks to our network of certified installers. In Europe, in addition to France, where our headquarters are located, we operate in the Czech Republic, Romania, and the French Overseas Territories. In Africa, our presence extends to Morocco, Senegal, and Tunisia.
We now aspire to expand our business in Italy and other African countries, and remain open to any proposals.
Replacing a traditional roof with a cool roof system represents an investment. But the initial cost is quickly offset by both significant energy savings and reduced maintenance requirements.
The IRR is therefore very favorable, as demonstrated by this building (see our other projects here).
Problem: Overheating in summer in a cold storage building.
Type of waterproofing: Bituminous membrane.
Description of the operation: Application of the CoolRoof solution on a 3,770 m² roof.
Instrumentation: Measurement of indoor/outdoor ambient temperature and indoor/outdoor surface temperature on buildings with and without CoolRoof. Application date: July 25, 2023. Analysis period: One year. Climate zone: H3.
Significant reduction in outdoor and indoor temperatures following the application of our CoolRoof solution. In addition to a 21% reduction in discomfort degree-hours, the CoolRoof has resulted in energy savings, financial savings, and a reduction in the building’s carbon footprint.
Cool roofing can be adapted to a wide range of buildings, from single-family homes to commercial or industrial buildings. Compatibility depends on the existing structure and energy objectives. However, a minimum slope (2 to 3%) is recommended for the roof to ensure good water drainage and optimal product efficiency. Generally speaking, if the building’s thermal resistance is less than 4.5 m2 K/W, CoolRoof provides very rapid results.
The CoolRoof solution can be applied to many substrates: glittery bituminous membrane, lacquered steel tray, porous concrete, natural tiles and slates, fiber cement, polycarbonate, fiber polyester, steel and aluminum. PVC, EPDM, TPO and smooth waterproofing membrane substrates are not currently compatible. It is not recommended to apply our CoolRoof to areas of water stagnation (flat surfaces).
Cool roofing helps reduce the energy consumption of buildings by limiting the need for air conditioning, which reduces greenhouse gas emissions. It is therefore beneficial for the environment by contributing to the reduction of global warming.
Regular maintenance is necessary to maintain the effectiveness of cool roofing (annual water cleaning is recommended), but can be difficult to achieve in areas where access to drinking water is limited. It is important to consider this aspect. Roof maintenance should be budgeted as an operational expense.
The application of reflective paint to the roofs of historic monuments requires approval from the Architects of Buildings of France (ABF).
For areas within a 500-meter radius of a historic monument, the final decision is made by the municipality, after consultation with the ABF. Even beyond this perimeter, it is mandatory to consult the local council. However, more and more municipalities are accepting this method, including in areas of remarkable heritage.
However, the green roof offers similar thermal insulation benefits that reflective paint does not.
However, a study from the University of Maryland published in July 2024 highlights cool roofing over greening to reduce urban heat.
In short, CoolRoof offers a practical, economical, and adaptable solution for most roofs. The two solutions are therefore complementary depending on the type of building. Greening professionals are struggling to find plants that can withstand increasingly high temperatures and longer heat waves.
These benefits demonstrate the positive impact of CoolRoof coating on energy efficiency, indoor comfort and operational reliability in various building types.
Solar radiation is composed of approximately 5% UV, 45% visible light (colors), and 50% infrared radiation. For an optimal cool roof effect, it is therefore necessary to reflect both visible light and infrared rays. The white color therefore only provides information on reflectance in the visible range.
Furthermore, to achieve a significant reduction in interior temperature, it is necessary to use a durable solution. Conventional white paint will not withstand the elements, will deteriorate quickly under UV rays, and will become heavily soiled. This is why the CoolRoof solution is composed of two complementary products, BaseCoat and TopCoat, allowing for results far superior to those of conventional white paint. The combination of these two layers ensures good adhesion and high thermo-reflective performance, and maintains them over time thanks to their anti-fouling and anti-UV properties.
Our CoolRoof coating consists of two complementary products for mechanical (Airless) or manual (roller, brush) application :
✖ We cannot say that our coating is an asbestos encapsulation solution.
Currently, there is no specific approval for asbestos encapsulation in France; however, certification is mandatory (company certification if work is carried out + ATEx/ATEc certification for products + Ministry of Health approval).
The prerequisite for encapsulation materials is waterproofing. Covering with a non-waterproof coating such as CoolRoof is possible for covering undamaged asbestos roofs; however, in this case, it is not possible to refer to it as “encapsulation.”
✖ Tests carried out at the Cool Roof laboratory have classified the CoolRoof coating as “non-waterproof”.
💡 Be careful not to confuse waterproofing with impermeability. CoolRoof coating is not waterproof, but it is impermeable to liquid water. It therefore has a certain resistance to water penetration.
Although our CoolRoof coating has very good abrasion resistance, it was not developed to be used under heavy traffic (such as on a sidewalk, for example), so we cannot guarantee its durability over several years in these conditions. However, there is of course no problem walking on the roof to carry out equipment maintenance, for example.
➡ The best performing CoolRoof will necessarily be white :
1. To be refreshing, the sun’s rays (UV + visible + near-infrared) must be reflected.
2. White reflects the fact that all visible solar rays are reflected.
3. The color reflects the fact that some of the (visible) solar rays are absorbed, and therefore contribute to heat absorption.
However, it’s worth considering this issue because in some cases, ultra-white can be problematic (glare, urban planning regulations, etc.). In this case, you should always favor a light appearance and ensure that solar reflectance in the near-infrared range remains at its maximum.
It is also important to keep in mind that, just as nothing will perform better than white, nothing will perform worse than black (which absorbs all of the sun’s visible rays).
Conclusion with an example : A “sky blue” cool roof will not perform as well as a white cool roof, but will still perform better than a black coating.
A priori, the impact of the CoolRoof coating on birds is the same as a snow-covered roof, for example. The radiation can therefore be dazzling in the immediate vicinity, but then it radiates diffusely without a focal point (it goes out in all directions).
No, the CoolRoof coating does not negatively affect rainwater quality. Analyses conducted by Labocea, an accredited laboratory specializing in water quality analysis, have confirmed that no organic pollutants from CoolRoof are detected in rainwater flowing from a roof treated with our solution.
In addition, recent tests conducted by Eurofins on the presence of PFAS (perfluoroalkyl and polyfluoroalkyl substances) in rainwater from roofs coated with our solution also yielded results confirming the absence of substances considered hazardous.
➡ We recommend annual maintenance using low-pressure water (< 90 bar) and a soft brush if necessary. Excessive pressure can damage and weaken the coating. Furthermore, our TopCoat has anti-fouling properties and a hydrophobic surface that allows water to flow easily and carry away dirt. Therefore, it is not advisable to use excessive pressure.
To maintain the reflective performance of the CoolRoof coating over time, annual cleaning of the entire surface is recommended. We recommend following these guidelines:
· Period: between March and May.
· Equipment: high-pressure deck cleaner (water-based), possibly using a rotating brush depending on the level of dirt. Finish with a rinse if necessary.
CAUTION: To prevent the CoolRoof coating from peeling off, the pressure of the cleaner should not exceed 90 bar (80 bar ideally)
with the lance positioned approximately 80 cm from the surface, using an indirect application (approximately 120° angle).
➡ In France, the CoolRoof tends to become dirty, particularly during the fall and winter. Therefore, it may be advisable to clean at the end of winter and before the onset of extreme heat (when periods of drought may limit water use).
Our CoolRoof coating has been specially designed for application over existing roof waterproofing. It does not adversely affect the existing waterproofing, as it is flexible, adapts to the movement of the roofing material, and also protects the waterproofing from UV rays and temperature variations.
Respects waterproofing : CoolRoof does not alter or improve existing waterproofing, whether for bituminous membranes or other materials. Its chemical composition, based on water-based acrylic, is similar to that of road paints.
Before any work, an on-site diagnosis is carried out to check the condition of the roof. If the waterproofing is defective, no estimate will be provided.
Outside the Scope of Ten-Year Civil Liability (RCD) : The CoolRoof is not considered a “structure” within the meaning of the regulations and is therefore outside the scope of the Ten-Year Civil Liability (RCD). The fact that CoolRoof is an innovative solution and a non-standard technique does not affect its insurability since the solution is outside the scope of the RCD (Residential Building Liability).
Performance and Durability History : Since 2015, approximately 1 million m² have been installed with CoolRoof without any liability under the RCD (Residential Building Liability).
In the event of work on a roof covered by the RCD (Residential Building Liability), it is up to the company that granted this right to the project owner to demonstrate that the CoolRoof caused any damage. However, CoolRoof does not affect the durability of existing waterproofing systems.
Future Work : If subsequent work is required on the structure, the application of CoolRoof poses no obstacle. Patching can be carried out at any time without changing standard practices.
Fire Rating : CoolRoof does not affect the fire rating of ICPE (Installations Classified for the Protection of the Environment) and is rated B ROOF T3.
It is not recommended to apply the solution at an ambient temperature below 10°C and/or when the humidity level is above 80%. Do not apply in case of strong winds/gusts of wind. Rainfall must be zero during application and for 24 hours following the installation of the coating.
To evaluate this performance, two properties are essential :
These properties are rated on a scale of 0 to 1. For optimal cool roof effect, they must be maximized.
To characterize coatings, the Solar Reflectance Index (SRI) is used, combining reflectance and emissivity. A higher SRI indicates a more pronounced cool roof effect.
Our CoolRoof from Cool Roof France has an SRI of 115, reflecting 90% of solar radiation and having a thermal emissivity of 90%. This exceptional performance means our coating is extremely effective at reducing absorbed heat and reflecting it, contributing to greater comfort and energy savings.
Cool Roofing is a solution for reducing urban heat islands (UHIs). By reflecting a large portion of the sun’s rays, it lowers the temperature of buildings and the ambient air.
This helps reduce energy consumption for air conditioning, lower energy costs, and lower greenhouse gas emissions, while improving thermal comfort.
Combating heat islands also requires a combination of green (planting), gray (urban surfaces, furniture), and soft (lifestyle management) solutions for optimal impact.
Cool Roofing is an innovative roofing solution designed to reflect a large portion of solar heat, thus reducing indoor temperatures in buildings during warm periods. However, its performance can vary in winter.
In winter, a cool roof can actually lose slightly more heat at night due to its ability to reflect heat accumulated during the day. This thermal loss is greater compared to a conventional roof, which tends to retain more heat inside.
However, this effect is generally moderate and may be negligible compared to the savings achieved in summer.
The choice to install a cool roof also depends on local climatic conditions and the building’s insulation. In regions with moderate winter temperatures, the benefits of reduced cooling costs during the summer can more than offset heat loss in winter. Furthermore, a good building insulation system helps limit these losses and maintain a stable indoor temperature.
In summary, although a cool roof may cause slight heat loss in winter, its benefits in terms of reducing air conditioning needs during the summer are significant. It is therefore a compromise to be evaluated according to the specific climate and the characteristics of the building, thus allowing the most suitable solution to be chosen according to the seasons.
On bituminous roofs, CoolRoof improves the operating conditions of thermal and ventilation equipment, reduces energy consumption for building cooling, and increases the lifespan of NVC equipment, while improving the electrical production of photovoltaic panels by up to 20% by lowering the temperature of their surrounding environment.
Above 25°C, a solar panel’s performance decreases. According to several studies conducted abroad, combining cool roofing with solar panels can create cool islands and improve their performance. Studies conducted by SolarWorld and Sog Solar show a power gain of up to 20% for bifacial photovoltaic panels and 7.6% for monofacial panels.
Using reflective roof paints reduces temperatures and improves the lifespan of roofs by limiting damage from solar radiation and weather. Additionally, it can improve the overall appearance of the building and reduce the urban heat island effect.
✅ The CoolRoof coating is suitable (adhesive) for asbestos fiber cement.
However, the conditions required for application are very restrictive :
⚠ In this particular case of asbestos fiber cement, the application must therefore be carried out by an approved and specialized company.
CoolRoof can be applied to the following metal surfaces: galvanized steel, stainless steel, and aluminum.
⚠ If there are any rust spots on the roof, it is imperative to completely remove them before application, either by sanding or with a rust converter. Otherwise, any remaining rust will resurface through the coating (red spots = flash rusting) and cause failures and peeling. CoolRoof is not an anti-corrosion protection, although it will resist sea spray (marine elements). Once the surface is clean and dry, apply a rust-resistant primer suitable for the substrate before applying CoolRoof.
Please contact us for more information.
The Cool Roof laboratory has validated a primer on galvanized steel (galvanized steel = steel coated with zinc).
➡
We will therefore consider that the primer proposed for galvanized steel is also suitable for zinc.
Furthermore, if the zinc sheet is new, it is (theoretically) recommended to remove the etching before applying the primer: either mechanically (sanding or sandblasting) or possibly chemically (using a de-etching agent).
Please contact us for more information.
❌ We do not recommend application to Derbigum SP FR roof waterproofing membranes.
This substrate has not been tested or validated in the laboratory.
The application on Derbigum presents several risks : lack of adhesion due to a smooth and incompatible support, and yellowing of the CoolRoof (or beige/brown color) due to diffusion phenomena between the membrane and the CoolRoof.
We have no experience with wood and have never carried out an application on this type of support, however:
➡ It is therefore essential to ensure the nature of the material that makes up the slate or tile. You must then refer to the usual recommendations: ✅ recommendations for fiber cement, concrete, slates or natural tiles. ❌ do not apply to plastic supports !
It all depends on the type of existing paint (polyester, polyurethane, epoxy, etc.).
✅ Generally speaking, our product can be applied, except in the case of Teflon-coated paint (a specific and rare condition).
⚙ If the surface is in poor condition (corrosion, defects, peeling of the existing paint), it is necessary to treat these defects, particularly rust spots in the case of rusty metal surfaces, and apply a suitable primer if necessary.
⚙ If the surface is coated with epoxy paint, it is recommended to sand the surface with a coarse grit (40 or 80) and thoroughly remove dust before applying CoolRoof.
⚙ If the surface is coated with anti-corrosion paint, it is advisable to keep this layer (and not sand it) because the CoolRoof product does not provide an anti-corrosion function.
Cool Roof teams mainly apply by mechanical means (spraying with airless guns), but the application can also be done manually (roller or brush). During the application, the use of the building is not impacted and the teams’ activity can continue as normal. The HP cleaning phase can be a little noisy, but it does not last very long in each area.
To maintain the reflective performance of the CoolRoof coating over time, annual cleaning of the entire surface is recommended. We recommend performing this cleaning according to these guidelines:
· Period: between March and May.
· Equipment: high-pressure deck cleaner (water-based), possibly using a rotating brush depending on the degree of dirt.
Finish with a rinse if necessary.
CAUTION: To prevent the CoolRoof coating from peeling, the pressure of the cleaner must not exceed 90 bar (80 bar is the recommended pressure) and the nozzle must be positioned approximately 80 cm from the surface, using an indirect application (approximately at an angle of 120°).
The use of high-pressure cleaners (90 bar) voids the warranty on any damage that may occur to the CoolRoof coating.
The Cool Roof solution is also available internationally. We are present on two continents thanks to our network of certified installers. In Europe, in addition to France, where our headquarters are located, we operate in the Czech Republic, Romania, and the French Overseas Territories. In Africa, our presence extends to Morocco, Senegal, and Tunisia.
We now aspire to expand our business in Italy and other African countries, and remain open to any proposals.
Replacing a traditional roof with a cool roof system represents an investment. But the initial cost is quickly offset by both significant energy savings and reduced maintenance requirements.
The IRR is therefore very favorable, as demonstrated by this building (see our other projects here).
Problem: Summer overheating in a cold storage building.
Type of waterproofing: Bituminous membrane.
Project description: Application of the CoolRoof solution to a 3,770 m² roof.
Instrumentation: Measurement of indoor/outdoor ambient temperature and indoor/outdoor surface temperature on buildings with and without CoolRoof.
Application date: July 25, 2023. Analysis period: One year. Climate zone: H3.
Baisse significative des températures extérieures et intérieures suite à lʼapplication de notre solution CoolRoof. En plus de la diminution de 21 % du nombre de degrés-heures dʼinconfort, le CoolRoof a permis des économies dʼénergie, des économies financières et une réduction de lʼempreinte carbone du bâtiment.
Most exterior paints are tested for 1,000 hours under ultraviolet (UV) radiation. The Cool Roof coating underwent very rigorous standardized tests (ISO 16474, ISO 11507) of 4,000 hours in an aging chamber, monitored by our R&D Department, where it was notably exposed to UV-B rays. This is a very rigorous test. After 4,000 hours under UV-B (ISO 16474), the Cool Roof coating maintained its overall performance, maintaining the initial SRI. An accredited test report (COFRAC) for measuring these properties on a smooth substrate is available.
At the end of the exposure, the Cool Roof coating showed no defects or yellowing and demonstrated excellent solar reflectance retention.
This high technical performance is due to the application of our topcoat, TopCoat. This resin has demonstrated exceptional resistance to aging, during many years of exposure in natural sites, particularly in Florida.
All of these elements allow us to guarantee that the CoolRoof solution’s thermal-reflective properties will be maintained for 20 years.
Adherence tests on bituminous membranes were also conducted at the CSTB, both in its initial state and after aging (heat and UV).
The Cool Roof France coating demonstrated good adhesion, even after undergoing heat or UV aging.
Cool Roof offers a two-year warranty on its products, requiring it to repair or replace, for a minimum period of two years after acceptance, any equipment that fails to function properly. Cool Roof also offers a perfect completion warranty, requiring it to repair all defects (hidden defects and non-conformities) reported within one year of acceptance of the work, regardless of their significance or nature. Cool Roof therefore guarantees its product (BC & TC) and its application for a period of two years from the date of the site acceptance report.
Starting in 2025, Cool Roof will implement a ten-year warranty, which will be mandatory and linked to a performance maintenance service (low-pressure cleaning).
This warranty covers :
The warranty is triggered as soon as Cool Roof becomes aware of a defect, whether it concerns the adhesion of the support or its loss of reflectivity.
On the roof :
Inside the building :
For the environment :
Financiers :
Cool Roof stands out by mastering the entire value chain, from R&D to application. Thanks to our expertise in materials chemistry, our thermal design office, and our field teams, we offer a high-value solution tailored to each building. Our coatings are eco-designed, non-polluting, and guarantee a low carbon footprint.
Our approach also incorporates a strong consulting component to ensure the effectiveness of each project. This includes:
Low-tech innovation for all