How Far Should A Flu Be Installed Above A Roof

When installing a new twinwall flue system if the flue exits the roof within 600mm horizontally from the ridge high point of the roof then the flue must extend a minimum of 600mm above the ridge.

How far should a flu be installed above a roof.

Set the collar with the wide flange at the bottom on the surface of the roof. Match the vent pipe to the furnace maker s recommendations either sheet metal or vinyl. Install no more than two elbow pipes at 45 degree angles if running the pipe through a chimney stack. In other words the highest point within a 10 foot circle of the pipe.

The minimum clearance may be reduced by 50 percent to 225 mm 9 in if suitable shielding is installed either on the pipe or on the combustible surface. Next roofing underlayment often made of building paper or felt is installed as the first weatherproofing layer for a pitched roof. For gas vents or a type l vent this distance above the roof surface must be at least 2 ft 0 61m. Minimum clearance from combustible material.

The top of the chimney should be at least 3 ft 0 92 m above the roof surface. Keep flue pipe as straight as possible for horizontal runs. Vertical blue line along the left side of the chimney in our photo. 450 mm 18 in.

If the pipe is farther than 10 feet from the roof peak it must be 2 feet above the highest point of the roof within 10 feet. If the flue exits the roof further down then it must extend high enough to acheive 2 3m of horizontal clearance. This specification makes sure steep roof slopes are cleared. Extend the vent pipe at least.

Place vent support straps along the pipe every 8 feet if it s more than 25 feet long.