Assembly and method for preventing water damage to insulated exhaust ducts

A method for installing an insulated duct of a ventilation system, the method comprising the steps of:

• providing an exhaust vent cap assembly, the exhaust vent cap assembly comprising:
• a tubular body, the tubular body comprising:
• a hollow tube having a proximal end and a distal end,
• a flange extends around a periphery of the proximal end perpendicularly to the hollow tube, and
• a mouth upstanding from the proximal end of the hollow tube,
• a cap configured to sealably fasten to the mouth, the cap and the mouth having a fastening mechanism, wherein an outer diameter of the cap is substantially same as an outer diameter of the mouth;
• making a hole in a roof deck, the diameter of the hole permits the mouth of the tubular body to slide into the hole;
• inserting the mouth of the tubular body into the hole, wherein the flange rests against an underneath of the roof deck;
• securing the flange to the roof deck using one or more screws;
• upon securing the flange, securing the insulated duct to the tubular body;
• and
• later removing the cap from the mouth;
• and
• upon removing the cap, installing a permanent roof cap.