Can I insulate the space between a brick chimney and the drywall inside my home?

I am getting heat transfer from the brick to the drywall in the summer from the sun heating the brick. My thermostat is located on that wall and is causing the a/c to run constantly due to the false reading of the temperature of the wall. That wall is warm to the touch. Even setting the thermostat at 80°F the actual inside temperature is 74°F in the house. There is about a 2 inch gap in the attic between the chimney. I thought about pouring insulation in this space. I converted to gas logs which are hardly used due to the North Carolina climate. Even when used there is not much heating of the chimney. I considered moving the thermostat but would have to run the wiring down the outside of the wall and drill down through the floor to reach the furnace under the crawlspace. The chimney is inside the structure not on the side of the house.

1 Answer 1


If there is a straight open space accessible from above, you might consider polyisocyanurate foam insulation. A 2 inch board has R-13 insulation.

You might want to consider a wireless thermostat. There are numerous types (both proprietary and wifi) that would allow you to move the sensor elswhere even if the base station was on the heated wall.


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