How Far Above Roof Should Chimney Extend

The chimney flue is the open shaft that runs from the firebox up through the chimney creating the passage for the fire smoke.

How far above roof should chimney extend. This specification makes sure steep roof slopes are cleared. The 10 foot rule explains the clearance you need. The top of a chimney pipe must extend at least 2 feet above the peak of the roof if the pipe is within 10 feet of the peak. Most wood stove and factory built fireplace manufacturers and local building codes will require that the chimney must extend at least 2 feet above any portion of any structure within 10 feet measured horizontally and must extend at least 3 feet above the highest point of its roof penetration.

If the pipe is farther than 10 feet from the roof peak it must be 2. There is a rule for this it s called the 2 3 10 rule. Both above the flat roof and 2 feet above the point at which a horizontal line from the chimney would touch the highest portion of the nearest roof. Select a chimney cap with a screen height 5 inches above your tallest flue at least 5 inches taller than the blue dotted line which metal is best for a top mount or multi flue chimney cap.

For gas vents or a type l vent this distance above the roof surface must be at least 2 ft 0 61m. They intend to make sure that the chimney draws properly and that a fire hazard does not occur. Most building codes require the chimney extend two feet higher than anything within ten feet horizontally. There must be at least 5 inches of clearance between the top of your tallest flue and the lid or roof of the chimney cap.

Continue reading below our video of the day. The top of the chimney should be at least 3 ft 0 92 m above the roof surface. Specifications aren t there to merely cause you problems. Vertical blue line along the left side of the chimney in our photo.

If it doesn t follow these steps to extend it.