The National Fire Protection Association (NFPA)’s 211 (Standard for Chimneys, Fireplaces, Vents and Solid Fuel Burning Appliances) is the standard that now classifies chimney and venting system inspections into three levels—Level I, Level II or Level III. Each level of inspection has a specific scope of work and specific criteria.
This inspection is recommended when the chimney and venting system is easily accessible and when the homeowner is planning to maintain its current use. In general, this the level of inspection performed in most homes. In a Level I inspection a certified chimney sweep verifies that the chimney structure is sound and that the chimney is free of obstructions and combustible deposits, such as creosote.
The addition of a new home heating appliance or a change in the type of fuel a homeowner is burning requires a Level II inspection. This inspection level is also required upon the sale or transfer of a property or after an operating malfunction or external event that is likely to have caused damage to the chimney. The scope of a Level II inspection includes that of the Level I inspection plus the inspection of accessible portions of the attics, crawl spaces and basements. It may also include a performance test such as a smoke test or a pressure test and possibly an interior chimney video inspection if recommended by the certified chimney sweep.
When a Level I or Level II inspection suggests a hidden hazard and the evaluation cannot be performed without access to concealed areas, a Level III inspection is recommended. This type of inspection confirms the proper construction and condition of concealed portions of the chimney structure and the flue. Level III inspections are generally necessary when investigating an incident that has caused damage to a chimney or building, or where a hazard is detected and suspected.
Both the Consumer Product Safety Commision and the National Fire Protection Association recommend yearly chimney inspections to help prevent fire and carbon monoxide poisonings.