Kitchen exhaust system. 7", 26 gage duct comes up from hood in a cabinet, two elbows to do an offset, goes up through the cabinet, penetrates attic floor above, keeps going up, two more elbows for another offset and connects to a roof cap. How do I support this? I'm guessing some kind of support right where it comes through the attic floor would work best, but I can't seem to figure out how. Duct also comes up in between two truss members that I could string some support 2x4s, but I'm at a loss as to how to attach the duct to this for support other than wrapping with ugly metal strap.