Q: Jason, I have 2 fireplaces, one below the other. There are 2 flues up the same chimney. The one in the basement has no damper and needs some work before it can be used, so we put a piece of concrete board over it and a bookcase to hold it in place to block the opening. Obviously, it wasn’t a perfect seal, but it was pretty covered.
We noticed though that when we used the upstairs fireplace smoke would come into the basement room. We want to use the upstairs fireplace this winter but aren’t ready to make a full decision on what to do with the basement fireplace. Would the Chimney Balloon be a good stop-gap solution until we decide whether to just block this fireplace off permanently or fix it? – MB
A: Dear MB, What you are referring to is called “smoke crossover” it happens when you have two chimneys close to each other and one is breathing out smoke while the other is breathing in outside air to equalize air pressure in the house. Here is a link to an article and a picture diagram of the issue.
The Chimney Balloon is used regularly buy chimney sweeps and homeowners to correct smoke crossover issues. If you use a Chimney Balloon to seal the basement fireplace chimney it will force the house to find another path to draw air in from other than the basement chimney flue. This, therefore, eliminates the smoke being drawn back into the house.
You can use the Chimney Balloon as a temporary or permanent solution to this chimney smoke crossover issue. The Chimney Balloon will function as your damper once it is installed so there will be no need to do anything with the old metal damper. So you can save the rest of the chimney funds to hit the other projects on the old honey-do list. – Jason
Where to Measure a Heatelator Pre-Fab Fireplace
Q: We have a 2 sided fireplace on the ground floor of our house and a 3 sided fireplace in the basement. Our house was insulated from electric heat. When we have a fire in one fireplace we get smoke coming back into the house through the other one. Would a chimney pillow stop the smoke from coming back in? Thanks very much for you help.- JU
A: Dear JU, Correct me if I am wrong, but it sounds like you have two separate chimneys for your two fireplaces they just share the same chimney structure? (like in the picture on the left)
If the answer is Yes, you do have two separate fireplaces and the flues are separate. Then the Chimney Balloon will stop the smoke from crossing over and re-entering the house through the other chimney. – Jason
Q: Jason, We have a 2 sided fireplace on the ground floor of our house and a 3 sided fireplace in the basement. Our house was insulated from electric heat. When we have a fire in one fireplace we get smoke coming back into the house through the other one. Would a chimney pillow stop the smoke from coming back in? Thanks very much for your help. – JJ
A: Dear JJ, Correct me if I am wrong, but it sounds like you have two separate chimneys for your two fireplaces and the two chimney flues go up one main brick chimney structure?
If the answer is Yes, you do have two separate fireplaces. Then the Chimney Balloon will stop the smoke from crossing over and re-entering the house through the other chimney flue. This is called smoke crossover. It is when the one chimney is breathing out air from the home and smoke from the fire mixed together, the other chimney is breathing in outside air to equalize the pressure in the home but is also sucking back in smoke.
Many people assume closing the damper on the unused fireplace will stop this crossover, but that is not the case. Dampers are not tight enough to stop this air draw. That is why a Chimney Balloon is needed in the unused fireplace to stop the air draw inward through the second flue. This forces the house to find another location to draw air in at where there is no smoke.
Q: Jason, I live in a main-floor condo with one upstairs neighbor. We have separate chimneys that are contained in one wood encasement. When my neighbor is burning a fire in his fireplace I have a strong smoke smell in my condo. My best guess is that the smoke is getting in through the top of the chimney. Is the seal on a Chimney Balloon tight enough to prevent this from happening?- MH
A: Dear MH, Maureen, This is a classic case of smoke crossover from one chimney to the other and it is a very common issue especially in apartments and condos, but it happens in homes with more than one chimney as well.
The answer to your question is, Yes, the Chimney Balloon will stop the smoke and odor from entering your home through the chimney. Your condo is “breathing in” through the chimney (which is often the path of least resistance for air entry into a home). And your neighbor’s condo is outputting smoke right next to your chimney. After putting in a tight-fitting Chimney Balloon your home will no longer be taking in air through the chimney. The air will find another entry point that is easier to draw through like a window or door jamb. This change of entry point will prevent the smoke from entering your condo. – Jason
Q: Jason, I figured an update might help someone unsure if this product works. I received and installed my Chimney Balloon a week ago and it has made a drastic difference! I am no longer smoked out! What a relief! Because my chimney was very small(9″ round),(and my damper door was angled in such a way that it was impossible to get my arm around it)I had a friend come over and help me remove the damper door, position the Chimney Balloon, and then reattach the damper. I am so glad I did. Thank you!- MH
A: Dear MH, Sometimes the damper hardware can be very difficult to contend with. I’m glad you applied your ingenuity to get past the troublesome damper hardware to solve the smoke chimney crossover problem. As you found the Chimney Balloon will seal the chimney flue tightly so the home will not “breath” through the chimney anymore and take in the other chimneys smoke. – Jason
Smoke goes up the one chimney and back down the other.
Q: I have a house built in 1870, and the flue I would like to seal appears to be very narrow, somewhat jagged, and irregular in shape. The best I can tell, the opening appears to be about 6 inches deep, and 12 inches wide. Which size would be best for me? And do you think there is a wider opening further up the chimney? If so, would I be able to push the Chimney Balloon up there and then inflate it??
Also, like Maureen in the previous post, I have a smoke situation and am hoping your product will help. We have multiple fireplaces, and when I burn a fire in the living room downstairs, smoke enters my son’s bedroom upstairs. They are in the same chimney. This started happening after we added a chimney cap to keep birds and animals out. The guy who did the work came back and claims he sealed the flue heading into the boy’s bedroom. But we had one more fire at the end of last season and still smelled smoke in his room during the fire downstairs. Please advise… – JW
A: Dear JW, Well, to answer your first question… I would go with a 9×15 Chimney Balloon for that size hole to plug. It does not matter much if the hole is jagged and rough in shape as long as the hole is not any larger than 9″x15″ and has roughly parallel walls on at least 2 sides.
On your smoke crossover question…Yes, the Chimney Balloon will give you a very tight seal on your unused chimney so the smoke smell will not be sucked back into the home. I’m sure your Chimney sweep gave it a good try to seal it up, but there is no way to get as tight of a seal as a Chimney Balloon will offer. Even a fiberglass bat plug will allow odor back in through it. – Jason