Chimney Balloon, Caulk, etc.: Insulate Your Fireplace

Prevent energy and money from going up the chimney.

On my fireplace I noticed very large gaps on either end of the damper. While it wasn't cold in the fireplace itself, heat was escaping up the chimney (that's what chimneys do, after all). To test this I lit a stick of incense and watched the movement of the smoke. Sure enough it quickly exited through the gaps.

Chimney Damper Gaps - A Chimney Balloon or Rope Caulk would help.
Damper Gaps in Chimney

Chimney Damper Gaps
Damper Gaps Shown In Red

There are several options for insulating your fireplace and preventing heat from being pulled out your chimney.

Chimney Balloons

These are probably the best solution for people who frequently use their fireplace but want to prevent drafts. In addition, if you aren't physically able to bend in awkward positions to put insulation or rope caulk in your fireplace this is the way to go.

Chimney balloons are essentially an air pillow that fits snugly at the top of the fireplace and blocks air from escaping. They cost $50-70. In general, they are easy to install and remove. They also receive good reviews as being easy to use and effective.

Fireplace Insulation

You can also purchase insulating board and cut it to fit in the top of the fireplace. This is a good option if you are good at measuring and cutting. Any gaps will be a source of air leakage so the insulation needs to fit snugly.

If you use the fireplace frequently, this solution could become tiresome and you may want to take a look at chimney balloons as an option.

Rope Caulk

Rope Caulk for Chimney This is probably the cheapest option, but it's a bit awkward to apply. Since it stops any air leaks, it is about as effective as the other options although it doesn't insulate.

Rope caulk is a soft, non-hardening caulk that comes in long ropes. It is fairly easy to apply, there's no mess, and you can remove it without any problem. I used about $1 worth to do my chimney.

First I wire brushed the chimney damper where I was going to apply the caulk. Then I wiped it down with a wet cloth. After it dried I put the caulk around the damper. The only difficult part was that it was a bit awkward applying the caulk.

Duct Tape

If it sticks, this will eliminate the major drafts but won't insulate. Still, the drafts are the major source of energy loss and this is far better than doing nothing. While it stuck (two days), this was an effective way to prevent air leaks in my chimney.

Sealing the Chimney

If chimney balloons, insulation board, or duct tape don't work there is one more option. You can have your chimney sealed by a contractor. This only works if you don't plan to use the fireplace again, ever. It's probably nice to mention it if you sell your house.

If you're worried that you or someone else will forget that there is a chimney balloon, insulation, or duct tape you can put a note on the damper lever. Hopefully the fact that the damper won't open should be a clue to someone using the fireplace.

In short...

Fireplace Get a chimney balloon if you use your fireplace frequently or you don't want to apply caulk or insulation. Either way you'll prevent energy and money from escaping up your chimney.

See more things you can do around your home.