What is Roof Jack?
The termination used where a run exits through the roof rather than a wall, common with interior second-floor laundry rooms. It works, but it sits in full sun and out of sight, so its damper is the component most likely to have gone brittle and stopped moving without anyone noticing. It also removes the homeowner's ability to check airflow by hand, which is the early-warning signal that catches most ground-floor problems.
