Fully encapsulated in aluminium foil for cleaner installation and resistance to grease or dampness ingress in service Traditionally, all ductwork used to be fabricated from metal. It required becoming encased inside of a fire defense procedure when passing through a compartment wall or ground without the assist of a fire https://fire-rated-ductworth36678.blogsmine.com/37256267/fire-rated-insulation-for-ductworth-for-dummies