Level 3 Chimney Inspection
The previous posts have covered a brief history of chimney sweeping along with what to expect on Level 1 and Level 2 Inspections that are recommended by the National Fire Protection Association. Again, you can see the entire code at the NFPA website for the Standard for Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances for further information and research.
If you have been following the progression of levels of inspection for chimneys then it will be no surprise that each level builds on the previous one. Since Level 1 deals with what can be seen without being invasive in any way and is determined by same circumstances for the appliance and; Level 2 takes it one step further as determined by different circumstances for your appliance and goes to places that can be accessed through doors, hatches and other entry ways as well as video cameras; then it makes sense that a Level 3 Inspection would be for cases when proper damage cannot be determined by one of the other two inspection levels.
If you cannot see the damage from a door or opening then access must be made by removal or destruction of permanent attached portions to buildings, structures or the chimney. Many times this is the only choice when there has been a fire in a residence or building that must be inspected as to cause or there has been a significant weather, seismic or other devastating event.
There are also times when a Level 1 or 2 Inspection leads to a Level 3 as there are situations and circumstances where you cannot see or detect a hazard without taking down a part of the structure to gain the necessary access. While this can be unfortunate, it is extremely important to exam any and all concealed areas of the chimney that is suspected of damage or malfunction.
While the purpose of a chimney sweep company may seem to be just cleaning the appliance so you can build a fire when you want, it is far greater than this. The real purpose is to make sure your chimney will function properly and as expected for the safety and enjoyment for you and your family. Anything less is not enough.