Cool roof for transport depots and workshops

A depot or a workshop is a single-storey building, very wide and rarely tall. The roof is by far its largest sun-exposed surface, and the main source of summer heat. When it is dark, it absorbs radiation and releases it inside for hours, including after sunset. Under that covering work mechanics, maintenance staff and operations teams, usually with no air conditioning. Treating the roof means acting on the cause of the overheating rather than on its effects.

Steel deck dominates on operations hangars, parking halls and newer workshops: it heats up fast and corrodes at overlaps and fixings. Older halls and rail workshops add glazed sheds and rooflights, which bring in light but also heat. On flat roofs, the bituminous membrane is still the majority: 80% of Covalba projects are carried out on membranes more than ten years old. Each substrate calls for a different system, confirmed by the diagnosis.

French law sets no maximum temperature above which work must stop. It imposes a safety duty: the employer assesses the risk linked to intense heat episodes and puts prevention measures in place, both organisational and technical. Measures that reduce solar radiation and heat build-up inside the premises are among the expected levers. A reflective roof belongs to that category: it treats the source of the overheating and its effect lasts all season.

A private operator can claim the CEE premium (French energy savings certificates) under the BAT-EN-112 scheme, reserved for tertiary and industrial buildings. The same works feed the décret tertiaire trajectory (French tertiary decree), which requires -30% of consumption by 2030, -40% by 2040 and -50% by 2050, reported on the OPERAT platform. A public operator or transport authority is more likely to use the Fonds Vert (French green fund), on its energy renovation and summer comfort strand.

A cool roof project takes place entirely on the roof. Machines stay on the ground and only the hoses go up: no roof removal, no storage area taken from traffic lanes, no vehicle to move out of the depot. The works last from a few days to a few weeks depending on surface area, with a prevention plan aligned with your service hours. This absence of interruption makes the operation feasible on a site that runs continuously.

On surfaces of several thousand square metres, the cost gap is decisive: €20-25/m² supplied and applied for a long-life cool roof, against €80-100/m² for a new membrane and around €150/m² for full insulation and waterproofing renewal. The coating protects the substrate from UV and thermal shocks and pushes back replacement by 8 to 10 years. Depending on the substrate, CovaMetal 20 treats steel deck and CovaSeal 20 restores waterproofing on flat roofs.