Projects / 1/5/2026

Heat under control

A new waterproofing system for the roofs of the Mapei France plant

The Mapei France plant in Saint-Vulbas, near Lyon, underwent a complete roof re-waterproofing intervention. The project involved the application of a high-performance Tecnocoat polyurea system to restore durability and improve thermal behaviour. The seamless membrane provides excellent mechanical strength, flexibility and watertightness without increasing structural load.

One of Mapei France’s production plants is situated in Saint-Vulbas, near Lyon. Its 2,500 m² flat roof was recently re-waterproofed by the roofing contractor Bousson Résines, using solutions developed by Tecnopol, a Mapei Group subsidiary, to create a durable, heat-insulated new roofing system.

One of Mapei France’s production plants is located in Saint-Vulbas, near Lyon. Its 2,500 m² flat roof was re-waterproofed using Tecnopol solutions.

The Tecnocoat system in action

The roof had been previously waterproofed with a bituminous membrane, consisting of a layer of polyester reinforced with slate flakes. On-site inspections revealed that the surface had deteriorated in several areas, mainly due to the adverse effects of UV rays. For the new roofing system, the designers opted for a polyurea waterproofing membrane, partly because of the material’s high mechanical strength and durability, and partly for its low density, which avoids increasing the existing structural load. After thoroughly cleaning the surface, the roofing contractor applied a coat of Primer EPw-1070 – a water-based, two-component epoxy resin – to improve adhesion between the substrate and the subsequent waterproofing systems. They then applied Tecnocoat P-2049, a fast-setting, two-component, hot-spray, pure polyurea membrane.

When mixed, its two components – Tecnocoat P-2049/A (isocyanates) and Tecnocoat P-2049/B (amines) – form a solid and seamless membrane that adheres perfectly to the substrate and ensures high flexibility and watertightness. With an application thickness of approximately 2 mm, this solution offers high mechanical performance and long-last-ing protection.

After the application of Primer EPw-1070, the roof surface was sprayed with Tecnocoat P-2049, a two-component pure polyurea membrane, to ensure watertightness and high mechanical performance.

A UV-resistant finish

Being constantly exposed to UV rays, the roof needs adequate protection to ensure that the waterproofing membrane retains its physical and mechanical characteristics over time. For this reason, on top of the Tecnocoat P-2409 membrane, the contractors applied Tecnotop 2C, an aliphatic polyurethane resin, in its white colour shade, specifically formulated to offer long-lasting protection against ultraviolet radiation. The Tecnocoat system is a “Cool Roof” solution based on the use of materials with high solar reflectance. This combination significantly reduces the roof’s heat absorption, keeping it cooler and improving thermal comfort inside the buildings in summer. It also yields considerable sav-ings in terms of energy consumption for cooling. Measurements taken on site reveal a reduction of up to 30°C in surface heat on days of intense sunshine, confirming the effectiveness of the technology. Lastly, the system has the additional advantage of being quick to apply. Olivier Bousson, Director of Bousson Résines, notes that “The system benefits from short drying times, so the primer, the polyurea membrane and the protective finish can all be applied on the same day – surface area permitting – thus reducing construction time and getting the system operational quickly.”