Because the pipe gets hot building codes require 1 in.
Clear attic furnace flue.
The opening around a furnace or water heater flue is a major source of warm air into the attic photo 5.
Remove the insulation between the joists where the flue is located to clear an area about 18 inches away from the flue on each side.
The vertical flue at the ceiling level is surrounded by and attached to a horizontal piece of open 1 2 x 1 2 metal mesh screen about 10 square.
American gas association has certified the design of condensing furnaces for a minimum of 0 clearance from combustible materials with a single wall plastic vent pipe.
I try to always design in some slop in spacing around mechanical equipment.
Apply a thick bead of high temperature caulk the flue on one.
This will stop the air from getting a free ride along the chase and heating your attic.
Nail them both on the attic floor so they butt up against the flue.
You can reduce creosote buildup in your fireplace flue by providing adequate combustion air which will encourage a hot clean burning fire.
Now i do have experience with technology change versus construction framing.
The metal furnace flue extends vertically through the closet ceiling through the attic and roof.
See direct vents side wall vents for a complete table of recommended clearance distances from a direct vent gas appliance terminal to other building components or features.
While you are at it look around for all other duct chases in your attic.
To check for creosote yourself first make sure there s no downdraft from the chimney.
Wipe it clear with a rag or soft cloth and then replace the cap.
Furnace flues require special sealing techniques the opening around a furnace or water heater flue or chimney can be a major source of warm air moving in the attic.
How to check for creosote.
Not much furnace experience around here that s just a heating coil on the end of the a c blower used for 7 8 weeks a year g.
Municipalities may require a minimum of 30 clear inches in front of the furnace which can be accomplished in a small room if the door to the room opens in front of the furnace.
From masonry chimneys to any combustible material including insulation.
Because the pipe gets hot building codes usually require 1 inch of clearance from metal flues 2 inches from masonry chimneys to any combustible material including insulation.
Cut away any branches or remove any object that might be obstructing the pipe and creating debris.
Of clearance from class b flues 2 in.
