18-28-604.11 Vapor retarders.
   If ducts used for cooling are externally insulated, the insulation shall be covered with a vapor retarder having a maximum permeance of 0.05 perms [2.87ng/(s- m 2 x Pa)] or less and is not required to be covered. All joints and seams shall be sealed to maintain the continuity of the vapor retarder.