The National Fire Protection Association says, “Chimneys, fireplaces, and vents shall be inspected at least once a year for soundness, freedom from deposits, and correct clearances. Cleaning, maintenance, and repairs shall be done if necessary.”

Maintenance Standards That Ensure Chimney Safety

Chapter 14 of the 2013 edition of NFPA 211 provides maintenance standards for chimneys, fireplaces and vents. The standards shed light on several important points. Here are a few examples:
 

• Clearances around chimneys, fireplaces and vents must remain unobstructed.
   
• Annual inspections provide early detection of problems that could cause fires, carbon monoxide poisoning or structural deterioration.
   
• If an inspection reveals that the chimney or vent installation is unsuitable for any reason, the installation needs to be redone to fit the standards. This may mean installing a larger chimney or correcting construction to meet clearance requirements.
   
• Cleaning of chimneys and fuel-burning appliance vents needs to be carried out whenever measurable deposits of creosote or other combustible materials are detected.
   
• If a chimney fire has occurred, extreme heat may have caused damage that cannot be seen with the naked eye. An inspection of the entire chimney, both interior and exterior, is the only way to ensure safe use in the future.
   
• If you move to a new home, standards dictate that you inspect chimneys, vents and flues before using fuel-burning appliances. Unused chimneys and vents sometimes become home to birds, rodents and other pests. Other hidden problems also may exist.

How to Meet NFPA 211 Standards and Keep Your Home Safe

NFPA standards define three levels of inspections.

Level 3 is the most detailed and is appropriate whenever hazardous conditions may exist. This level is required if it appears that construction of the chimney area or clearances are inadequate or that safety may have been compromised by some event, such as an earthquake or lightning strike.
Level 2 is appropriate for newly purchased homes or if changes to the system are anticipated, such as switching from an oil-burning furnace to one that uses natural gas. It requires a visual inspection of all internal surfaces, including flue liners and joints. The most common method of meeting this requirement is video scanning with special cameras. In addition to all the actions required in a Level 1 inspection, a Level 2 inspection checks clearances anywhere there is available access for the inspection.
Level 1 specifies the minimum actions required for a routine annual inspection, which includes making sure that the chimney or vent is free of combustible deposits and obstructions, checking for basic soundness regarding the installation of the fuel-burning appliance and its connections, and making visual inspection of all parts of the exhaust gas venting system that can be seen without the use of cameras or other equipment.