Passive fire protection for metal ventilation and smoke extraction ducts, with mineral wool

System for passive fire protection of rectangular section vertical metal ducts to ensure EI 15 fire resistance according to UNE-EN 1366-1, by covering with 60 mm thick mineral wool panels, according to UNE-EN 14303, thermal conductivity 0.031 W/(mK). Including electro-soldered rivets for fixing the panels to the metal surface, stainless steel helical screws, 180 mm long, for joining longitudinal joints between insulating panels, intumescent paste in water-based base for fireproofing metal ducts between fire sectors, incombustible and inorganic adhesive, based on sodium silicate, for fireproofing the junction between mineral wool and the substrate, and L-shaped profiles, galvanized steel, 30 mm for reinforcing the junction between mineral wool and the substrate.