The context
The Lyon Gerland TGV maintenance centre (technicentre) services high-speed trainsets in multi-track halls that operate around the clock. The roofs of these buildings, covered with PVC membranes, build up heat in summer and release it into volumes where maintenance teams work permanently. SNCF Voyageurs entrusted Hélios with the application of an athermal coating on the roofs concerned, under a contract signed in June 2026.
The project
Three buildings were treated between July and September 2026: the two smaller ones first, then the large maintenance hall, which alone accounts for more than 8,000 m². In total, more than 10,000 m² of roofing received the PrimaTherm® system for PVC membranes, without interrupting the site’s activity. The works were accepted on 17 September 2026, without reservations, with handover of the as-built file: monitoring sheets for each building, thickness checks, quantities applied, warranties.
The constraints
- Continuous operation: halls in activity, trainsets moving, shared working with the SNCF teams.
- Railway safety: prevention plan, authorisations, supervised access and walkways.
- PVC membrane more than ten years old: prior adhesion test, then the PH107PVC bonding base instead of the primer.
- No lifting: drums and machines on the ground, only the hoses go up — no crane near the tracks.
- Phasing: two stages of works and invoicing, aligned with the availability of the buildings.
The system applied
On a PVC membrane, the PH107PVC bonding base replaces the primer; it is followed by the PH107 reflective base coat and the PH107TCL anti-soiling topcoat. Certified values: solar reflectance 95 %, emissivity 0.89, SRI 120, Broof(t3) fire rating. Each building underwent a thickness check, has its own monitoring sheet and is included in the as-built file handed over at acceptance.
Further reading
- Cool roof in Lyon — our projects across the metropolitan area, 15 km from our head office.
- Cool roof for industrial buildings and warehouses and logistics.
- Cool roof on waterproofing membranes — bitumen, EPDM and PVC over ten years old.
