Reinstate the fire resistance effectiveness of wall and ground constructions Uninsulated ventilation duct assemblies are intended to be used in environments in which the clearance to combustible supplies and combustible assemblies is at the least 18 inches. What's the difference between fire-resistive rated duct assemblies and fire-protecting rated duct assemblies? https://johnnyrhvkx.myparisblog.com/37596569/fire-rated-ductworth-for-dummies