The gas furnace was in a garage and the flue pipe went up through the above attic.
Insulation around flue pipe.
However the better method for filling voids in a chimney flue liner to the full height of the flue is to use vermiculite chips can be bought for insulation purposes or as soil treatment check around for best prices.
I wouldn t worry much about not having a square foot of insulation here and there.
Compress the insulation around the rigid liner by hand until the two edges snap and lock together.
The pipe comes out of the wall into the garage and up to the roof.
Cut enough aluminum flashing from the roll to wrap around the vent pipe with an extra 6 inches to spare.
It was covered with blown in insulation.
This makes it an ideal insulation material for use in areas that experience high temperatures.
Do not use spray foam for any of the joints near a vent pipe.
I was thinking of doing some better framing around it and maybe use rigid foam insulation but i read that building code requires a 2 gap around.
Always use fire resistant caulking.
In this case the b vent was also dented on the side so i know the airspace around the double wall pipe was compromised.
It had about a 5 rise from the furnace to the charred area in the attic.
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.
You should never have insulation in contact with a wood stove flue pipe.
Available in 24 lengths.
Now you must form an insulation dam to prevent insulation from contacting the flue pipe.
I am reinsulating this wall and i need some advise on how to insulate this.
You worry for good reason.
Fiberglass insulation is naturally fire resistant.
The opening around a furnace or water heater flue or chimney can be a major source of warm air moving in the attic.
Most code jurisdictions require the stove pipe be routed through a thimble to provide a safe distance from combustible materials.
I don t know about a dryer vent but for most heaters and woodstoves it is not allowed.
I have added a picture.
It is often installed in gaps around the chimney and flue to prevent airflow that can siphon the heat away from the interior of the building.
Apply a thick bead of high temperature caulk the flue on one side.
As such it can be used to insulate a chimney.
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.
Probably a less heat loss than a window.
Air traveling over the surface of the flue pipe may be required to keep it safe and cool.
Rigid insulation increases the outside diameter of the liner pipe by 1 75.
