Grease duct joints are held together by means of shaped V clamps and sealed with 3M Fire Barrier 2000+. CE & UKCA marked Integrity (E): Integrity failure shall be deemed to obtain occurred if any of the following are observed: Integrity failure occurs within the unexposed aspect as described in https://mylesrhviv.blogdiloz.com/35853508/a-simple-key-for-grease-tight-extract-ductwork-unveiled