The minimal duct thickness is described by whichever code jurisdiction that the undertaking is located in. Down below are two code references associated with the expected thickness and substance kind for grease ducts. Remove and soak in hot drinking water with a robust hood degreaser Scrub totally with non-abrasive brushes https://rylanbsjyl.blogsvirals.com/35806654/commercial-kitchen-extract-systems-for-dummies