Insulation Around Chimney In Attic

You can insulate around masonry chimneys after airsealing with mineral or fiberglass batts no foam or cellulose directly against the chimney.

Insulation around chimney in attic.

You can wrap the masonry with a 3 5 fiberglass batt and then blow cellulose up to the batts. Fiberglass insulation is commonly used in attics around the chimney stack. Measure the circumference of the flue. Spun fiberglass insulation is like a sponge as far as its ability to collect and hold significant volume of water.

Cut two flat sheets of aluminum flashing that are 14 inches long and narrow enough to fit between the ceiling joists around the flue. The b vent system requires air space clearance as well as clearance from combustibles. Because the pipe gets hot building codes usually require 1 inch of clearance from metal lues 2 inches from masonry chimneys to any combustible material including insulation. It is an effective barrier to the passage of heat.

Due to pressure differences caused by stack e. How to insulate a metal flue pipe. Don t you still need a 2 clearance to combustables. For diy attic insulation you ve got two choices.

Loose fill or batt the common term for blanket insulation. Both can be added to uninsulated attics or layered over existing material. In hot climates it prevents heat from outside the house entering reducing the need to use air conditioners. Fibreglass is not considered non combustable correct.

In either cse it fills the required open air space around the b vent in the un conditioned attic space. Furnace flues require special sealing techniques the opening around a furnace or water heater lue or chimney can be a major source of warm air moving in the attic. Holes hidden in attics basements and crawlspaces are much harder to locate and usually cause bigger problems. Turn the water heater or furnace off and allow the flue to cool to the touch.