how would you insulate a roof jack?
This past winter I seem to have had an incursion of water through a roof jack that connects to my range hood via an 8" duct. Since we were not in the house all winter (summer home) I don't know if it was condensation from the cold on the escaping heat or if it was just snow/rain coming through the flap. This is the first time that this has happened in the three winters we have had the house. The result of the water incursion was some warped wood floof boards.
So my questions are: 1) Can the roof jack be insulated to prevent heat loss and condensation? If so, how can it be done? 2) What if anything else should I do to keep the winter weather out of the roof jack but still be able to use the vent hood (now that we live here year round)?