CE & UKCA Marked Uninsulated ventilation duct assemblies are meant for use in environments the place the clearance to combustible products and combustible assemblies is at the very least eighteen inches. ROCKWOOL Curtainrock® is actually a stone wool insulation board created for use in ASTM E2307 examined and approved perimeter https://josuethwky.theideasblog.com/37343530/not-known-factual-statements-about-fire-rated-insulation-for-ductworth