Does Your Chimney Stack Up?
By: New Jersey Home Inspector Michael Del Greco
Does Your Chimney Stack Up?
Submitted by: Michael Del Greco, New Jersey Home Inspector Lic GI 0121, President of Accurate Inspections, Inc, a New Jersey home inspection company
Not all chimneys are created equal. There are accepted standards for chimneys, some of these standards vary based on geographic location and local ordinances.
How high your chimney should be: Your chimney should be at least two feet (2\') above any portion of the building within ten feet (10\') of the chimney and at least three feet (3\') above the point where it passes through the roof.
What size flue the chimney should have: Your chimney should not be smaller than the collar from the heating appliance.
How far the chimney should be from combustible material: The chimney should be two inches (2\'\') if it is built partially or entirely within the structure, and one inch (1\'\') if it\'s built outside the structure.
The height requirements for metal chimneys: The height requirements for metal chimneys are the same as for masonry chimneys: at least two feet (2\') above any portion of the building within ten feet (10\') of the chimney, and at least three feet (3\') above the point where it passes through the roof.
How to know your fireplace will draw without lighting a fire: Generally, you can know if your fireplace will draw without lighting a fire by checking just a few things:
1) Check for smoke stains on the front of the fireplace or mantle. These stains indicate that something has gone wrong. What that is will be determined later, but there is a problem if stains are present. However, if a fireplace is new or if the mantle has been recently painted, the stains may not be evident.
2) Check the size of the flue and firebox opening:
a. The chimney flue should be one-tenth (if square or rectangle) to one-twelfth (if round) the size of the firebox opening or larger (e.g., an 8\'\' x 12\'\' chimney flue, or 96 square inches, should have a firebox opening of 960 square inches, approximately 30\'\' x 32\'\').
b. The chimney should be two feet (2\') above the roof or any roof structure within ten feet (10\') and a minimum of three feet (3\') above the roof.
c. Other criteria such as the throat and smoke shelf should be considered. However, if the flue to the firebox ratio is correct and the chimney height is acceptable, the chimney will probably draw.
Most chimneys meet the basic requirements. If yours is not one of them, you probably would have figured out by now that something is wrong. Consult a local home inspector or a chimney specialist from a recognized chimney association. Chimneys should be cleaned after every cord of wood is burned!
Information provided by Michael Del Greco, New Jersey Home Inspector Lic. GI 0121, American Society of Home Inspectors Member 102273, Pesident of Accurate Inspections, Inc. A West Paterson New Jersey Home Inspection firm.