· Michael Blair
Chimney inspections are standardised into three levels, and the difference between them is how much of the system gets looked at and how much has to be opened up to do it. Most homeowners buy a level one without knowing there is a level two, and there are specific situations where only the second will do.
Level one, the annual check
A visual inspection of the readily accessible parts of the chimney and the appliance connection. The sweep checks the structure and the flue for soundness, looks for obvious damage and obstruction, and evaluates the amount of creosote or soot present.
It is the correct inspection when nothing has changed: same appliance, same fuel, same usage, no problems, no work done. That describes most households most years, which is why it is the common one and why it is normally bundled with an annual sweep.
Level two, and when it is required
Everything in a level one plus the accessible parts of the chimney exterior and interior, including attics, crawl spaces and basements where the chimney passes through, and a video scan of the flue interior along its full length.
It is called for on a property sale or transfer, after any change to the system such as a new appliance, a fuel change or a relining, and after any event that could have damaged the chimney: a chimney fire, an earthquake, a severe storm or a lightning strike. Those are not optional occasions.
- Level one: annual, visual, nothing has changed
- Level two: sale, appliance change, or after any damaging event
- Level three: opening up structure where a serious hazard is suspected
- A video flue scan is part of level two, not level one
- Buying a house with a fireplace warrants a level two
What the camera finds that eyes do not
Cracks in clay flue tiles, particularly after a chimney fire, which expands and shears the liner in ways that are invisible from the fireplace opening. Gaps in mortar joints between tiles. Missing sections. Damage where a flue passes through a floor or an attic.
This matters because the flue liner is what keeps combustion products and heat away from the framing around the chimney. A cracked liner in a chimney that is being used is a path for carbon monoxide into the house and for heat into the wall, and it is not visible from either end.
The Nashville timing argument
The right time to inspect is late summer or early autumn, before the first fire. Sweeps are booked solid from the first cold snap onward, and a chimney found to need relining in November is a chimney out of service for the part of winter you wanted it for.
Late summer also means any animal that moved in during spring is found before a fire is lit under it, which is a common and avoidable Middle Tennessee problem. Chimney caps prevent it and are inexpensive, and their absence is one of the first things an inspection reports.