Until recently, the scope of work performed in the inspection or evaluation of a fireplace, stove or other venting system was generally up to the discretion of the chimney service technician. Professional service technicians now have an industry standard that removes much of that "discretion". The National Fire Protection Association (NFPA) has addressed the minimum chimney standards in its latest publication (NFPA-211) concerning home heating appliances.
Inspections are now classified as Level 1, Level 2 or Level 3.
Below is an explanation of the three levels of inspection as provided by the Chimney Safety
Institute of America and the National Fire Protection Association.
Level 1 Inspections -If your appliance or your venting system has not changed and you plan to use your system as you have in the past, then a Level 1 inspection is a minimum requirement. A Level 1 inspection is recommended for a chimney under continued service under the same conditions and with the continued use of the same appliance. Most chimney sweeps include a Level 1 inspection during a routine cleaning.
In a Level 1 inspection, your chimney service technician should examine the readily accessible portions of the chimney exterior, interior and accessible portions of the appliance and the chimney connection. Your technician will be looking for the basic soundness of the chimney structure and flue as well as the basic appliance installation and connections. The technician will also verify the chimney is free of obstruction and deposits.
Level 2 Inspections -A Level 2 inspection is required when any changes are made to the system. Changes can include a changes in the fuel type, changes to the shape of, or material in, the flue (I.E. Relining), or the replacement or addition of an appliance of a dissimilar type, input rating or efficiency. Additionally, a Level 2 inspection is 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. Building fires, chimney fires, seismic events as well as weather events are all indicators that this level of inspection is warranted. A Level 2 inspection is a more in-depth inspection then a Level 1 inspection.
Level 2 inspection includes everything in a Level 1 inspection, plus the accessible portions of the chimney exterior and interior including attics, crawl spaces and basements. It will address proper clearances from combustibles in accessible locations. There are no specialty tools (i.e. demolitions equipment) required to open doors, panels or coverings in performing a Level 2 inspection. A Level 2 inspection shall also include a visual inspection by video scanning or other means in order to examine the internal surfaces and joints of all flue liners incorporated within the chimney. No removal or destruction of permanently attached portions of the chimney or building structure or finish shall be required by a Level 2 inspection.
Level 3 Inspections -When a Level 1 or a Level 2 inspections suggests a hidden hazard and the evaluation cannot be performed without special tools to access concealed areas of the chimney or flue, a Level 3 inspection is recommended. A Level 3 inspection addresses the proper construction and condition of concealed portions of the chimney structure and the flue. Removal or destruction, as necessary, of permanently attached portions of the chimney or building structure will be required for the completion of a Level 2 inspection.
A Level 3 inspection includes all the areas and items checked in a Level 1 and a Level 2 inspection, as well as the removal of certain components of the building or chimney where necessary. Removal of components (i.e. chimney crown, interior chimney wall) shall be required only when necessary to gain access to areas that are the subject of the inspection. When serious hazards are suspected, a Level 3 inspection may well be required to determine the condition of the chimney system.