There are many approved ways of creating a welded joint for grease exhaust ductwork. The alternatives will depend upon the code in your jurisdiction but really should contain flanged, telescoping, Bell form or overlapping joints. ROCKWOOL ROXUL Safe and sound® is usually a stone wool fireblocking insulation meant to fill https://greasetightextractductwor46788.bloginder.com/37610576/5-essential-elements-for-fire-resisting-ductwork-insulation