Here is some information useful for most homeowners regarding chimneys:
• Any chimney venting a wood burning appliance should be cleaned annually or every 60 fires by a qualified chimney sweep to prevent creosote from building up and potentially causing a chimney fire.
• In specific cases, a masonry chimney flue or a pre-fabricated chimney can be connected to more than one appliance, as long as the chimney or vent is correctly sized based on the heat output capacity of the chimney/vent.
A flue venting a wood burning fireplace cannot be used for any other purpose. Because the rules for venting wood burning appliances are complicated, it is always best to check with a qualified Wood Energy Technology Trained (WETT) contractor regarding the vent- ing of wood burning appliances
• Some other common deficiencies that are usually identified during a home inspection with respect to chimneys include inadequate clearance to combustibles around chimneys and flue vents (the required clearance varies, depending on the chimney, its location, and what it is venting), missing spark arrester/rain cap on masonry chimney flues (These prevent moisture or pests from entering the chimney flue), inadequate or improperly sealed roof flashing around the chimney, and inadequate chimney height (A general rule is that a chimney should be 1m above the roof line and 60 cm above anything within 3.18m of the chimney).
Areas that are not visually accessible during the inspection cannot be inspected, such as proper clearance to combustibles behind walls and/or the condition of the interior chimney flue.
Verifying that the flue is properly sized for the appliance(s) being vented is outside of the scope of the inspection since the output capacities of the appliances are required to perform the sizing calculations and these values are not typically readily available.
The home inspection focuses primarily on safety issues, and not code issues, so commenting on the chimney’s code compliance are also outside of the scope of the home inspection.
For more information on AmeriSpec’s home inspection services in Cambridge, Kitchener, Waterloo, Guelph, Georgetown, Brampton, Caledon, Bolton or Orangeville, call us at 1-800-794-5880 or visit our website. You will also find other Ask the Home Inspector articles on home maintenance, health and environmental issues and home energy efficiency.
