Is painting the EPDM membrane white a good idea?

There are a number of solutions for ensuring the watertightness of a building's roof. Among the possibilities for waterproofing a flat roof, the EPDM membrane is considered one of the most reliable solutions. With its long service life and excellent waterproofing properties, EPDM is a safe bet. However, this membrane has one major drawback: it absorbs a great deal of heat. To combat the heat, it is possible to apply a cool roof white reflective coating to the EPDM membrane of your building. Covalba explains all.

What is an EPDM membrane?

When it comes to roof waterproofing, there are many solutions available in mainland France. However, in the case of a flat roof, certain standard solutions are not applicable. This is particularly true of tiles, which are useless on a flat roof. That's why professionals have developed solutions adapted to flat roofs.

This is how EPDM membranes arrived in France in the 1960s. EPDM is a rubber derivative obtained by copolymerizing ethylene and propylene. The resulting material is highly resistant. Today, EPDM has a wide range of applications: automotive, thermal insulation and roof waterproofing.

An EPDM waterproofing membrane takes the form of a plastic film that is unrolled over the entire surface of the flat roof. Thanks to its excellent waterproofing faculties, EPDM roofing reviews are very positive.

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Why change the color of an EPDM membrane?

Although EPDM has many advantages, it's not a perfect solution. In fact, this roofing material has a number of disadvantages, one of which is particularly significant for professionals: heat absorption.

This absorption results in an increase in the building's interior temperature. During heat peaks or summer periods, the impact can be particularly strong, raising the temperature of the protected building by more than ten degrees.

This is due to the albedo of EPDM. In its most classic form, EPDM is black, like other rubbers. Albedo refers to a material's ability to reflect the sun's rays: the darker the color of a material, the closer its albedo is to 0, and the more heat it absorbs. Conversely, the closer the albedo is to 1, the less heat the material absorbs (this applies to all light-colored materials). In the case of EPDM, the albedo value is almost zero, as the membrane absorbs most of the radiation.

To overcome this problem, the color of the EPDM membrane can be changed. The color with the best albedo value is white. However, white EPDM membranes are not currently available on the market. To optimize the thermal performance of your waterproofing solution, EPDM membranes can be painted white.

How do I paint an EPDM membrane white?

A white EPDM membrane is a waterproofing solution for flat roofs that has been recolored white. This change in color is intended to reduce heat. For the tint to be truly effective, however, it's important to choose a paint with optimum performance. With this in mind, Covalba offers a highly effective reflective paint for cool roofs.

Cool roofing is a technical solution that has been gaining ground in France for several years now. It consists of using a white heat-absorbing paint on roofs to reflect the sun's rays. The CovaTherm paint distributed by Covalba has a Solar Reflectance Index (SRI) of 119, the highest in Europe. Thanks to this paint, it is possible to maximize the performance of its white EPDM membrane, gaining up to 10 degrees inside the building and saving up to 40% on electricity bills.

When cool roof is applied, the entire surface of the flat roof is treated. This ensures uniform reflection of the sun's rays. This solution has a lifespan of up to 20 years.

Is a white EPDM membrane effective?

Using a white EPDM membrane on a building is extremely effective. In fact, thanks to the CovaTherm paint used, the maximum surface temperature of the roof is halved, from 80 degrees to 40 degrees Celsius.

Within the building, this translates into a drop in interior temperatures of up to ten degrees. For manufacturers, retailers, shopping malls and logistics professionals, the white-painted EPDM membrane solution saves electricity costs by significantly limiting the use of air conditioning.

To find out more :

• How much does waterproofing a flat roof cost?
  
• All you need to know about Liquid Waterproofing Systems (LWS)
  
• Waterproofing capabilities of steel roofs
  
• The co-ownership's responsibility for roof maintenance
  
• What you need to know about reflective waterproofing
  
• Re-application and alternatives for maintaining your waterproofing solution
• How to maintain a flat roof, and what to do in the event of a leak