Insulation Around Flue Pipe

The pipe comes out of the wall into the garage and up to the roof.

Insulation around flue pipe.

Fiberglass insulation is naturally fire resistant. I wouldn t worry much about not having a square foot of insulation here and there. 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. Rigid insulation increases the outside diameter of the liner pipe by 1 75.

I have a fireplace insert in my basement. Compress the insulation around the rigid liner by hand until the two edges snap and lock together. In this case the b vent was also dented on the side so i know the airspace around the double wall pipe was compromised. Available in 24 lengths.

Most code jurisdictions require the stove pipe be routed through a thimble to provide a safe distance from combustible materials. 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. Unless the manufacturer says you can pack insulation around the pipe don t. It was covered with blown in 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. 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. I am reinsulating this wall and i need some advise on how to insulate this.

Cut enough aluminum flashing from the roll to wrap around the vent pipe with an extra 6 inches to spare. At least you can keep air from flowing around the pipe. I have added a picture. As such it can be used to insulate a chimney.

Always use fire resistant caulking. It had about a 5 rise from the furnace to the charred area in the attic. Probably a less heat loss than a window. You worry for good reason.

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. This makes it an ideal insulation material for use in areas that experience high temperatures. Air traveling over the surface of the flue pipe may be required to keep it safe and cool. I don t know about a dryer vent but for most heaters and woodstoves it is not allowed.

The gas furnace was in a garage and the flue pipe went up through the above attic. Do not use spray foam for any of the joints near a vent pipe.