Terrific post Alison! While we prefer sheet metallic, especially for trunk traces, substantial duct programs could be exorbitantly expensive if carried out in all steel. There are times where by flex duct (or sections of it) may also help to scale back fees. In our retrofit work, we’d fairly see https://greatbookmarking.com/story18298620/5-easy-facts-about-fire-rated-ductwork-described