Great post Alison! While we like sheet metallic, especially for trunk traces, large duct systems could be exorbitantly high priced if finished in all metal. There are occasions where flex duct (or sections of it) can help to cut back costs. Inside our retrofit do the job, we’d instead see https://freebookmarkpost.com/story18152805/fire-resistant-ductwork-installers-things-to-know-before-you-buy