It’s a basic standard for chimney construction which states that the chimney should extend 3 feet above the roof penetration on the shortest side, and the top of the chimney must be at least 2 feet above any part of the house structure within 10 feet. The rule is intended to make sure the chimney is tall enough so that any nearby parts of the structure will not interfere with the necessary draft to exhaust combustion gases. While this is a good basic standard, following the 3-2-10 rule does not guarantee that a chimney will not have downdraft problems.
While we hope you find this series of articles about home inspection helpful, they should not be considered an alternative to an actual home inspection by a local inspector. Also, construction standards vary in different parts of the country and it is possible that important issues related to your area may not be covered here.
© McGarry and Madsen Inspection
