CovaTherm

A dark roof soaks up as much as 90% of solar radiation, then pushes that heat into the building. A reflective roof coating flips that, through two combined properties.

• Solar reflectance: how much radiation the coating bounces back instead of soaking up. A good reflective coating clears 0.85.
• Thermal emissivity: the ability to release accumulated heat in the infrared range. The best formulations reach 0.90.

Combining the two gives the SRI (Solar Reflectance Index), the ASTM 1980 standard indicator used as the industry reference. The higher it is, the better the coating performs. CovaTherm 20 reaches an SRI of 119 when new and 118 after accelerated aging, among the best-performing on the market.

Reflective coatings aren’t all the same. The resin technology decides how long the coating actually lasts.

• Acrylic resin: 90% of the market. Around €10 to 12/m². Degrades quickly under UV and chalking, with a useful life of 2 to 5 years.
• Polyurethane resin (CovaTherm): €20 to 25/m² installed, lasts 8 to 10 years with a simple maintenance coat. With anti-UV Top Coat (CovaTherm 20): 20 years with no intermediate touch-up.

Over a building’s operating life, the cheapest coating to buy is always the one that costs the most.

A professional reflective roof coating, installed, runs €10 to €25 per square meter, all-inclusive: assessment, surface preparation, material, and application. Most of the gap comes down to the technology used.

• €10 to 12/m²: acrylic-resin reflective coating, service life 2 to 5 years.
• €20 to 25/m²: high-performance polyurethane-resin reflective coating like CovaTherm, service life 8 to 20 years depending on the finish.

Three additional factors move the final figure: the area to be treated (price tapers off above 2,000 m²), the condition of the substrate, and the geographic location of the project.

For comparison, a new waterproofing membrane costs €80 to €100/m², and a full insulation + waterproofing replacement runs around €150/m². So a reflective coating cuts the budget by 3 to 7 times, with an average ROI of 14 months. Estimate the savings of a reflective roof coating.

How a reflective roof coating performs comes down to how well it goes on. A Covalba project runs in five controlled steps, done by certified applicators.

1. Technical assessment: A technician evaluates the condition of the substrate, measures moisture, identifies areas to repair, and checks material compatibility. A poorly assessed substrate means a coating that blisters.
2. High-pressure cleaning: Removal of moss, dust, and residue with a pressure washer, without stripping. This step determines long-term adhesion.
3. Primer application: A bonding undercoat preps the substrate to take the reflective coating.
4. Base coat application: The reflective coat is applied in two crossed passes, sprayed from the ground. Zero load on the roof, zero vibration, zero risk to the existing waterproofing.
5. Top coat application: On the long-life version only, this anti-UV and anti-soiling finish protects reflectivity for 20 years.

It all goes on in dry weather, 10 to 35 °C. A typical 1,000 m² project wraps in 3 to 5 days, with no downtime for the building. Every applicator is PPE-certified and trained to work safely up top.

The durability of a reflective roof coating comes down to three things:

• Its resistance to UV
• Its resistance to soiling
• Its ability not to chalk

A standard coating can lose up to 40% of its reflectivity in 5 years, which cancels out much of the initial thermal benefit.

CovaTherm 20, thanks to its exclusive anti-UV Top Coat, maintains an SRI of 118 after 4,000 hours of accelerated aging in a QUV chamber, equivalent to 20 years of solar exposure. The coating soils three times slower than standard solutions and does not chalk. It is among the best-performing for durability on this type of product.

The choice between a reflective coating, a new membrane, and a full renovation depends on the building, the budget, and the current state of the roof. Here are the criteria that matter, and why a reflective coating makes a strong alternative to waterproofing replacement.

A reflective coating pays back the fastest, with nothing torn off and no downtime. It’s the go-to choice for industrial, pharmaceutical, food-processing, aeronautical, and commercial buildings more than 10 years old, where keeping cool is critical and a heavy renovation is hard to organize.