In addition to photovoltaic panels, you can improve the energy performance of your buildings in a consistent and cost-effective way by insulating your roofs.


Soltis offers solutions for the renovation and insulation of flat roofs.

We work to improve :
-Insulation (petrochemical: PIR/PUR or sustainable: cork)
-Waterproofing: installation of EPDM or bitumen membranes

Soltis is approved to install EPDM membranes of the brand RESITRIX® BRAND brand EPDM membranes, and for the installation of Derbigum® brand bitumen membranes. . For you, it's an additional third-party guarantee.

We also produce extensive green roofs.

Contact us to discuss your project

5 reasons to choose Soltis

  • + More than 15 years' experience
  • A Belgian SME on a human scale, with personal contact from A to Z
  • 10-year guarantee on the watertightness of your roof
  • The guarantee of quality workmanship that meets current standards
  • Soltis is the specialist in sustainable insulation with natural materials
  • Complete management of administrative procedures (obtaining subsidies, etc.)


Read theinterview with our specialist Frédéric Béguin for APOK (Belgium's leading distributor of roofing materials).

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  • I am an individual
Our services
  • Third-party investment
  • Electric charging.stations
  • LED lighting
  • Photovoltaic panels for businesses
  • How do we guarantee the watertightness of your roof for 10 years?
    Whether or not your roof is guaranteed watertight for ten years depends on a number of factors:
    1. If the roof is in good condition, i.e. recent, with a roof covering in sufficiently good condition and an under-roof, we can guarantee watertightness. In this case, the initial condition of the roof is essential.
    2. If the roof is in poor condition at the base, we cannot guarantee that it will be watertight. That's why we ask that the roof be sufficiently recent.
    3. An old roof in very good condition can also be considered, but we also check whether the roof is insulated. Before installing solar panels, we recommend prioritizing insulation work. Although insulation isn't always mandatory for all structures (e.g., a barn), it's best to follow a logical order in the work.
    4. We emphasize the importance of insulation before installing solar panels. If the roof is not insulated and watertight before the panels are installed, we cannot guarantee watertightness. It makes more sense to carry out the work in sequence, to avoid expense and potential delays. Installing solar panels and having to dismantle them in a few years' time to insulate them is a waste of time and money. In short, we guarantee waterproofing if the roof is in good condition, sufficiently recent, and if there is a good under-roof.
  • How can we contribute to the energy transition?
    Years of carbon-free electricity generation.
      According to the International Energy Agency(IEA), it takes between 2 and 3 years for a solar panel to generate the energy required to produce it. This figure is constantly falling, thanks to the ongoing development of panel performance. Given that the lifespan of an installation is between 25 and 30 years, that's as many years of carbon-free energy production. A real boost for the climate!   What's more, as Greenpeace details in this article, "... panels are 95-99% recyclable for most manufacturers. Whether they were built in China or Europe..."
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Your benefits


Soltis guarantees long-lasting insulation. We usually work with natural insulating materials (cellulose made from recycled newspaper, high-density wood fiber, hemp...) that ensure the building breathes. This reduces the risk of condensation and gives you a healthy home, insulated from the cold in winter and the heat in summer.


The insulation of your building has an impact on your energy bill. And natural insulants are now available at comparable prices, with regional bonus premiums. Depending on your region, our experts can assist you in obtaining subsidies.

Performance and comfort

Soltis respects 3 main principles to guarantee energy efficiency and pleasant comfort:

  • Sufficiently thick natural thermal insulation (healthy, cold-resistant in winter and heat-resistant in summer) for up to 30% more energy efficiency!
  • Perfect airtightness. This is the ability to prevent the passage of air from the outside to the inside and vice versa, while allowing the building to breathe through membranes open to diffusion (Gore-TexTM principle). This offers up to 15% extra energy performance!
  • Hygienic ventilation, controlled and maintained by regular maintenance, to extract humidity from the home.

Our specialities

Flat roofs

petrochemical or natural cork insulation. We are approved to install Resitrix® membranes, the top EPDM product for flat roof waterproofing.
EPDM (ethylene-propylene-diene monomer) are special elastomers introduced to the market in 1963, offering a service life 3 times longer than that of a conventional membrane. This membrane is certified root-resistant, enabling immediate installation of a green roof.

Green roofs

intensive and extensive.

Do you have any questions?

See our FAQ or Contact us online

other services

services for Companies

Third-party investment

Electric charging.stations

LED lighting

Photovoltaic panels for businesses