Replies

1. 
   CableRigger | Dec 13, 2008 04:49am | #1

   I'm going to guess that both fireplaces share a single flue, in which case it's no surprise that you have this problem, especially when their fire is dying out. As the chimney cools and there isn't enough heat/smoke to create a good upward draft, the smoke begins to settle and go back down the chimney- so it winds up coming down to and through you leaky damper. If you don't use your fireplace, you could probably stuff some fiberglass insulation (no kraft paper or any kind of facing) up above your damper and that might help out.

   If the fireplaces each have their own flue, you might consider a damper that attaches to the top of you flue - a top-sealing damper as they are called. Many online sources for them - Lyemance is a popular choice. However, I don't think it is likely that you do have separate flues as you wouldn't get much if any at all issues as you describe.

   An even better solution is to get yourself a wood stove and run it continuously. Since it is then pretty much a sealed system (not much smell as stove is dying out), your neighbor upstairs will be the one complaining.

1. 
   seeyou | Dec 13, 2008 05:15am | #3

   I'm going to guess that both fireplaces share a single flue

   That's highly unlikely. I was a chimney sweep for 8-9 years and I only ever saw that once and it was an add-on situation.http://www.quittintime.com/      View Image        

1. 
   CableRigger | Dec 13, 2008 05:33am | #4

   My house (built in 1921) has five fireplaces and two chimneys, each with two flues.

   Furnace uses one of the flues in one fo these chimneys, the other flue is shared by THREE fireplaces! One in walk-out basement and two back-to-back in kitchen/dining room above. I have a wood stove in basement and another in the dining room, never use the kitchen fireplace (since stove & oven produce enough heat when cooking meals) and damper was missing when we moved in so I simply shoved fiberglass insulation up that one.

   Other chimney has upstairs (bedroom) and downstairs (living room) fireplaces, each with their own flue. However, on the back side of the living room fireplace, there is a hookup for a wood stove flue pipe (for another bedroom).

   So if you count, I can potentially have seven sources of combustion hooked up to four flues. Maybe rare in Kentucky, but we require a bit more heat here in Connecticut.

    

1. 
   seeyou | Dec 13, 2008 12:22pm | #6

   Other chimney has upstairs (bedroom) and downstairs (living room) fireplaces, each with their own flue. However, on the back side of the living room fireplace, there is a hookup for a wood stove flue pipe (for another bedroom).

   OK - that's a bootleg hook-up and you can't use the f/p and stove at the same time.

   Furnace uses one of the flues in one fo these chimneys, the other flue is shared by THREE fireplaces!

   Potentially a dangerous situation and certainly not approved by any applicable code. http://www.quittintime.com/      View Image        

1. 
   jayzog | Dec 13, 2008 03:35pm | #12

   In my area there is many houses built in the 1800s, They all have multiple fireplaces on single flues. You either have to burn them all at once or block off the ones not in use real well.

2. 
   CableRigger | Dec 13, 2008 04:09pm | #13

   Code? What Code? Built in 1921 by the guy who lived here the next 50+ years.

3. 
   seeyou | Dec 13, 2008 04:27pm | #14

   Code? What Code? Built in 1921 by the guy who lived here the next 50+ years.

   The codes that were enacted after that to save people from themselves. NFPA 211 is the primary code that most other codes are based on.

   And before you say "It works perfectly fine in my house", there's lots of grandfathered situations out there that work but it doesn't mean you're not living on the edge using that system.

   You know, it's funny. Everytime a house burns down from chimney related issues, the chimney is usually left standing

   Hell, I've driven home drunk with bad brakes on bald tires in a blizzard with no winshield wipers. Made it just fine. But my odds of making it were lower than if I was sober with good equipment.http://www.quittintime.com/      View Image        

2. 
   Piffin | Dec 13, 2008 03:33pm | #10

   "Maybe rare in Kentucky, but we require a bit more heat here in Connecticut."It is rare all over the country because it is unsafe, no matter how much heat you need. 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

2. 
   Piffin | Dec 13, 2008 03:27pm | #9

   It is not all that common ( especially in modern places where it is against codes) to have shared flues, but what could be happening is close to the same physics, if they share the same chase ( I don't know if this is masonry of metal) is that the use of the FP in one place creates a negative pressure in the building so that air ( and smoke) is being drawn into the building via his flue. 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

2. 
   seeyou | Dec 13, 2008 05:12am | #2

   I have the flue closed ,

   I'm assuming you mean you have the damper closed. The flue is the tube the smoke exits through. The damper is (usually) metal plate that closes the air flow off.

   This is a common problem with two flues in a shared chimney. When the upstairs fireplace is burning, make-up air is necessary to replace the combustion air which must come from outside somehow. Negative pressure is created inside the house so make up air is pulled through whatever holes it can find. Your downstairs flue is one of the holes and your damper is an ungasketed piece of metal (possibly warped) resting against another piece of metal. Not exactly an airtight situation.

   The upstairs smoke exits the top of the flue and a little of it gets pulled back into the downstairs flue. The remedies are:

   1- Extend the downstairs flue by a foot or so if you use your fireplace on occasion. This can be accomplished by added a piece of the appropriately sized flue tile if you have masonry fireplaces. If they are prefab, you have to purchase the proper brand and size of flue pipe. Every brand has proprietary components.

   2- Install a chimney top damper. Since it's away from the intense of the firebox, it's gasketed and provides a tighter seal.

   3-Seal up the damper with some type of gasket/insulation. Easiest and cheapest, but not practical if you burn the fireplace.

   http://www.quittintime.com/      View Image        

1. 
   gossamershavings | Dec 13, 2008 10:48pm | #15

   damper, yes.it also is a bit warped. I had thought of blocking it off, but we want to use it upon occasion.some good advice by everyone.thanks to all.i will let you all know if/how i fix it.

3. 
   Taproot | Dec 13, 2008 06:01am | #5

   I would agree with the folks who say that this likely a downdraft problem. If you have a forced air heat, this could also contribute in that air is being pulled down the chimney to return to your air handler (check and change your filters often!!).

   I've seen people address (solving may be another matter!) this in a couple of ways.

   One would be take out your damper and take it to your local wood stove/fireplace dealer and ask if there is a sealant you could use (like the seal you use around a wood stove door). Taking out the damper may not be an option depending upon how the fireplace was constructed and even with this, it may not stop the leaks. (And note, this will be a messy job, be prepared!)

   Another product I've seen on the web but never used personally is a flue sealer that inflates. You can see more about that here:

   http://www.willygoat.com/catalogmultiple.asp?runstart=555&showinfo=0&name=fireplace%20draftstopper%20flue%20sealer%20-%20small&attempt=3&site=2

   You can buy it from a variety of places, that's just one I found easily through Google. This seals the flue and stops drafts, i.e. it seals the flue for YOU, not everyone else, in that you put it up your flue about a foot above the fireshelf. If this fireplace is not active for you, then this may be a good way to go.

   The last is more aesthetic and is one that I've seen. This was a large, cast-iron cover for the fireplace itself that rests up against the outside of the fireplace and basically seals off drafts, but also looks nice (it usually has some decoration on it). I cannot locate any via a quick search of Google, but it might be worth checking out. I've seen them work and it was a nice solution (and likely expensive).

   Good luck!

   Tim

4. 
   Henley | Dec 13, 2008 02:56pm | #7

   Good advice all around.

   Another possibility is they are running the fireplace
   with THERE damper to far closed.
   Causing it to smoke slightly into the house.Which would
   end upstairs in your place.

1. 
   theslateman | Dec 13, 2008 03:05pm | #8

   The OP lives below the smoky fireplace in question.

1. 
   Henley | Dec 13, 2008 03:34pm | #11

   Oops, thanks for the correction.

5. 
   notagain | Dec 14, 2008 12:05am | #16

   I've installed a number of Lymance top mounted dampers which, IMO, would be the best way to deal with your situation.

   They are painted aluminum, sized to a particular flue, and rubber gasketed to seal out air, critters, rain, etc.

   Here in CT there are many early homes with center chimneys, 3, 4, & even 5 fireboxes all dumping smoke into the same stack. Not ideal by any means, but many are still in use. If I had one I'd teardown to the 2nd floor floor, and rebuild with dampers and flue tile for each firebox.

   But that can get expensive. Without spending too much money, the minimum I would do is to install dampers in each firebox so that you can close down which fireboxes are not in use.

   I know.........cast iron dampers are not airtight.......the keyword is minimum.

   Back to the op's question..........top mounted damper is the way to go. It would more than likely solve the problem , surely the first thing to do.

   Rod

   
   

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   Edited 12/13/2008 4:05 pm ET by notagain