Two partners from the Lyon area, one trade: making roofs reflective
Hélios Solution Cool Roof was born from the meeting of two partners from the Lyon area, Enzo D’Adderio, president, and Antoine Mendez, managing director, convinced that a large part of the French industrial and tertiary building stock overheats for a simple reason: its roofs are dark. Rather than adding kilowatts of air conditioning, we treat the cause — the solar radiation absorbed by the roof — with a certified reflective coating, applied according to a strict protocol.
The company is an SAS (French simplified joint-stock company) registered with the Lyon trade register (SIREN 940 314 164), with its head office at the Parc d’activité des Platières in Saint-Laurent-d’Agny (Rhône). From there, our teams cover the whole of France, French-speaking Switzerland, Belgium, Luxembourg and the French overseas départements.
What we do, and what we do not do
We are applicators of the PrimaTherm® system manufactured by Prima Coating. In practical terms:
- we diagnose your roof (satellite measurement, visit, adhesion tests) and say frankly when a surface is not compatible — asbestos-cement, PVC membrane that is too recent;
- we apply the four layers of the system (primer, reflective base coat in two passes, topcoat) without lifting equipment: drums and machines on the ground, only the hoses go up;
- we check: thicknesses, quantities per zone, infrared measurements before/after, site monitoring sheet, as-built file;
- we guarantee: ten-year (décennale) insurance, system guarantee, completion guarantee.
We do not manufacture coatings, we do not sell new waterproofing, and we do not display a price per m² on this page: every proposal is priced on your building, after a study.
Why PrimaTherm®
Because its values are measured by independent laboratories and not declared by a marketing department: 95 % solar reflectance (ASTM E903-12), emissivity 0.89 (ASTM C1371-15), SRI 120 (ASTM E1980) — maintained after 4,000 h of accelerated QUV ageing —, Broof(t3) fire rating (CSTB report RA23-0010). The reports are attached to every proposal. See the PrimaTherm® certifications.
Our references
In 2026, Hélios treated 5,900 m² of roofs on the Airbus site in Marignane, an aerospace site in operation, with −29 °C measured on the surface at handover; then the Le Bourget aerospace site and the SNCF TGV maintenance depot in Lyon Gerland. EGGER and SET Corp also place their trust in us. These sites are documented in our projects and our customer testimonials (in French); prospects under study never appear there before signature and agreement on communication.
How we work with you
- Free study, answer within 48 h: you describe your building, we come back with a satellite measurement, the thermal potential and the pre-qualified incentives — CEE sheet BAT-EN-112 under conditions, the French Green Fund (Fonds Vert) for local authorities.
- Technical visit and proposal: adhesion, condition of the surface, access, operating constraints; line-by-line costing.
- Application without lifting equipment, site in operation, phasing to suit your constraints.
- Documented handover: measurements, as-built file, guarantees, maintenance plan.
The details are on the how we work page.
Our commitments
- Proof first: every figure published on this site comes from a test report or a site measurement; the ranges are cautious and the incentives are never promised.
- Safety: prevention plans, working-at-height certificates, client site protocols (aerospace, rail) respected.
- Transparency: we say when a cool roof is not the right answer — waterproofing at the end of its life, incompatible surface, building without a heat issue.
- Accessibility: a team you can reach on +33 4 82 53 16 44, Monday to Friday from 8 am to 7 pm, and contacts who have themselves applied the system on a roof.
Are you a homeowner?
For a house or a small area, our PrimaTherm® online shop (in French) sells the coating with a quantity calculator per m² and the roller application guide. For a residential building under co-ownership, ask for the study: the reduced 10 % VAT on French homes over two years old applies.
We are hiring
Hélios is building a network of independent applicators: building companies, tradespeople and sole traders trained on the PrimaTherm® system, to whom we bring the projects, a fully equipped van, the tools and the product delivered on site. Details on the become an applicator page (in French).
Frequently asked questions
Is Hélios the manufacturer of the coating?
No. PrimaTherm® is manufactured in France by Prima Coating (Périgny, Charente-Maritime). Hélios is an applicator: we diagnose, prepare, apply according to the manufacturer’s protocol, check and guarantee. We also sell the coating to homeowners through our online shop (in French).
Where are you based and where do you work?
Our head office is in Saint-Laurent-d’Agny, in the Rhône département, about thirty kilometres south-west of Lyon. We work throughout mainland France, in French-speaking Switzerland, Belgium, Luxembourg and the French overseas départements: Marignane, Paris-Le Bourget, Lyon, and soon your site.
Who actually applies the coating on my roof?
Our applicators, trained in the PrimaTherm® protocol, holding working-at-height certificates, supervised by the founders. No intermediary: the company that studies your roof is the one that applies the coating and guarantees it.
What insurance and guarantees do you offer?
Professional liability and ten-year (décennale) insurance (certificate attached to every proposal), a 10-year PrimaTherm® system guarantee on the thermo-reflective performance, a one-year completion guarantee and a two-year equipment guarantee, as set out in our as-built files.