What is the thickness of the fire-rated duct? A fire-rated duct needs to be made with just one pores and skin, using a whole thickness not exceeding 2mm. This measurement contains the intumescent coating, that is important for improving fire resistance. In accordance with the Environment Well being Organisation (WHO), https://fire-rated-insulation-for24566.blog-kids.com/39738123/fire-resisting-ductwork-specialists-an-overview