Belzona, a leading manufacturer of polymeric materials, says recent Solar Reflectance Index (SRI) testing has demonstrated that its cool roof coating, Belzona 3111 (Flexible Membrane), exhibits high solar reflectance properties with an average* SRI of 99.4 per cent.

This finding underscores the valuable role of polymeric technology in mitigating the escalating global warming impact of increased air-conditioning use.

What is a Cool Roof?

A cool roof strongly reflects sunlight and efficiently emits absorbed heat. To measure this effect, SRI testing examines a material's solar reflectance and thermal emissivity. The SRI, a value that combines these figures, is used to indicate how hot a material will likely become when its surface is exposed to solar radiation. It ranges from 0 (standard black) to 100 (standard white).

Materials with lower SRI values are likely to absorb more solar energy, which is conducted into buildings and structures, leading to increased internal temperatures and a higher demand for air-conditioning. This significantly contributes to greenhouse gas emissions.

According to NREL and Xerox PARC research, air-conditioning accounted for 3.94 per cent of global greenhouse gas emissions in 2022, equivalent to 1,950 million tons of carbon dioxide annually. This figure is projected to rise as global temperatures increase, leading to a predicted 14 per cent increase in air-conditioning use in the hottest climates studied (Chennai, India) and 41 per cent in the mildest (Milan, Italy) by 2050. This research highlights a self-reinforcing cycle that necessitates improved cooling for both human health and climate stabilisation, says Belzona.

Protection with Cool Roof Coating

Cool roof coatings like Belzona 3111 (Flexible Membrane) play a crucial role in minimising this expected growth in air-conditioning use, says Belzona.

The cold-applied liquid coating is designed for long-term roof protection.

“This single-component, water-based coating offers outstanding waterproofing and weatherproofing properties, adhering strongly to various roofing materials and conforming even to complex roof contours,” says Isaac Atkinson, Technical Coordinator. “Certified by the British Board of Agrement and ETA-Danmark (European Technical Assessment), this isocyanate-free system has demonstrated excellent roof protection for more than 25 years.”

When tested in accordance with ASTM E1980-11, Belzona 3111 (Flexible Membrane) in white achieved an average SRI of 99.4 per cent, reflecting its optimised solar radiation rejection, he adds. This translates to a significant reduction in internal temperatures when applied to roofs. This figure can be used to demonstrate compliance with building codes in cases where measured solar reflectance and thermal emittance figures do not independently comply.

Reduced Costs and Environmental Impact

Commenting on the test results, Atkinson says: “Belzona 3111 (Flexible Membrane) has an important role to play in helping to alleviate the destructive cycle of increased air-conditioning usage. Coating roofs with this cool roof system will help to reduce internal temperatures, enabling asset owners to significantly reduce the need to use air-conditioning and thus not only make significant financial savings, but to reduce their carbon footprint.”

Other benefits cited for Belzona 3111 (Flexible Membrane) include:

•  Its simple brush or roller application minimises downtime;

•  Improves occupant comfort by minimising heat gain inside buildings;

•  Provides long-term weatherproofing and waterproofing protection; and

•  Reduces health and safety risks due to being a solvent-free system.

Belzona 3111 (Flexible Membrane) has already been applied on a number of projects in the Arabian Gulf region, according to its manufacturer.

Established in 1952, Belzona is a leading company in the design and manufacture of polymer repair composites and industrial protective coatings for the repair, protection and improvement of machinery, equipment, buildings and structures.  It has more than 159 distributors in more than 120 countries.  In the GCC these include Hatcon Industrial Services in Bahrain and Saudi Arabia; Adel Behbehani General Trading Company in Kuwait; Advanced Oilfield Technology Company (AOTC) in Oman; Apollo Enterprises in Qatar; and Molecular Corrosion Technologies in the UAE.

* Average figure based on SRI calculated in low, medium and high winds.