Smoke in basement from upstairs fireplace

12 years ago

I have a 1965 home with an up/down fireplace (both flues in one chimney). We've always had a problem with smoke from the basement fireplace when we are using the upstairs fireplace. A recent inspection showed many cracks in the upstairs flue joints. The chimney company repaired the cracks with cerfactory (sp?) cement saying that was the reason for the cross-smoking. Well our first fire today and smoke again! I'm at a loss. The fireplace has a fresh air inlet and both flues have Chimilator top mount covers. The basement's is closed.

Any ideas??

Sort by:Oldest

Comments (5)

mpinto
12 years ago
Oh my goodness, I could have written this myself! I have the same set up and same problem. We had the upstairs flue relined and new dampers put on both. Our downstairs one is also closed. Nothing has worked. I have been reading about chimney heights and think mine is too short. Smoke is getting trapped between the chimney (side of house) and a valley in the gabled roof. I am having a mason come out and look into extending it, but also to make the upstairs flue taller than the basement one. This is supposed to help with the draft and get rid of negative pressure. I hope it works. I'll let you know what the mason says.
berlin
12 years ago
The problem has little to do with the similar height of both flues; you shouldn't be getting a downdraft down either one of them if the chimney was built properly. If you have an exterior chimney with the flue opening (top) lower than the lowest interior part of your home, you will definitely have problems. The stack should actually be a bit higher than the highest exterior (ridge line of roof) portion of the home - especially on an exterior chimney. It is sad that so many builders and masons don't know and often don't care about the proper functioning of a chimney. the 10/2 rule is a minimum requirement for a builder to pass code, NOT a recommendation on what SHOULD be done. Nothing other than extending the stack to its proper height will solve your problem permanently - and if the mason or "chimney professional" you hire says othewise, FIRE HIM. This is why the poor original poster spent lots and lots of mony to no avail - she dealt with chimney professionals more interested in selling her unnecessary liners than understanding and fixing the real problem.
Related Discussions
jotul wood burning insert smokes
Q
Comments (9)
Make sure you neutralize the pressure in the room its in by opening a window, if you dont have a pressure problem in the house you may need to extend the chimney. You are on the very cusp of the manufactures minimum rating and you have that longer then average offset..I think thats most of the problem. You extend the chimney buy using a anchor plate and a transition plate. The transition plate would be optional if you have a good way to attach the anchor plate to the current liner. Normally it would be installed like this: Transition plate covers the chimney and the flange for connectiong the liner points down the chimney The anchor plate bolts to the top of the transition plate and provides a connection for the class A chimney,. If it wouldnt look too rediculious i would add 4 more feet. If you have a negative pressure problem in the home, (if cracking the window improved things dramaticly) then you have a complete other set of problems to deal with. go to www.duravent.com and look up the three parts. You will need the transition plate, the anchor plate, and what ever length of pipe you need. This is a whole nother can of worms, but the stove might perform worse in the basement. There are absoluty no guarentees that your basement will provide a better installation then what you currently have. To make a long story short, your house is one large chimney, heat rises in the attic positivly pressurizing the attic, the main level of the home is is a pass through point, and is typically neutral, and the basement is the supply, wich is under pressure because there isnt much air that can get in the basement, making it negative for pressure. That means the new chimney that is way up in the air has a pretty postive pressure at the top, and the stove at the bottem is in a negative room, and becomes the appliance that tries to neutralize the basement. The stove could be thought of as the same effect of opening a window to neautrlize a room. You can imagine the potential draft problems...
...See More
Smoke from fireplace flue being drawn down flue for furnace
Q
Comments (1)
Soo... This stack is an exterior stack that terminates 2' above the peak? It terminates therefor at least 2' above the HIGHEST portion of the home, not just where it exits? IF NOT then that is the problem, the chimney was never built properly; even it it 2' above the highest portion of the home, that's not tall enough, a minimum of 3' is barely adequate, and 4' is minimum recommended. Having said all that, What "chimney professional" talked you into chimney caps? What "problem" were you trying to solve with them? Have them REMOVED and solve your problem. It's likely that the second flue always had a week and occasionally reversing draft due to improper chimney height, but the caps (which are, in most cases, unnecessary) have caused this unseen problem to become visible. You have three options: 1. extend the chimney height so that it functions like a proper chimney should. 2. Remove the caps! (you have some aversion to this, but it works and will cost you less than the other options). Remove furnace connect from basement flue and disable furnace (not very likely a good choice).
...See More
Two flews; get smoke from one to the other
Q
Comments (2)
There are three things this could be. 1. Mortar joints between the flue tiles are missing. If a camera was ran up the flue and mortar joints were in tact still then this is not the problem. Wood smoke is acidic it reacts with the lime in the mortar and the sand falls out. When the mason lays the clay tiles he just used the same mortar used to lay the brick. Usually a type n or s mortar. It is supposed to be a high temp refractory cement but a lot of masons don't use it. If the mortar joints are missing between the flue tiles there is a smoke crossover between the gaps within the chimney. Causing the issue. This normally happens in reverse though. Basements are low pressure zones in the house air likes to flow to the negative. and a chimney is a good place for make up air within the home. This is the scary part. If the mortar joints are missing and the smoke is crossing over through one it's probably happening with the gas unit too. But instead of the form of smoke it's carbon monoxide. 2. Smoke chamber. Same theory is applied here as well. Wood smoke is acidic and smoke is passing through the gaps between the bricks because the sand has fallen out of the mortar 3. Smoke crossover at the top of the chimney. This is most likely not the problem since it normally happens in reverse. (make up air comes in the basement) easy way to test this theory though. Turn off the pilot and block off the top of the flue and see if it smokes. Smoke chamber is probably the issue and 800$ isn't a bad price. There is typically a lot of labor involved and 2 people have to work on it. One inside and one outside. Unless the sweep has a chamber parging system.
...See More
Fireplace surround / mantel - basement - which to go with?
Q
Comments (5)
Thank you! I have to get the tile by Monday! I‘m also looking for opinions on tile size. The space is approximately 9’ long by 4’ high. The fireplace is 6’ x 2’. So the tiled space will be 17“ on each side of the fireplace and 12” above and 12” below. Could I use a 12x24 tile or do I need to go smaller? Thanks!
...See More
mjolson5
Original Author
12 years ago
Well, problem solved. Our ancient model of Chimilator wasn't sealing well and we were indeed getting a downdraft into the basement. The chimney repair guys formed a gasket to improve the seal and now the problem is gone.
berlin
12 years ago
The "problem" is solved because he sealed the damper, but you wouldn't have had a downdraft in the first place if the stack was the proper height for your home.
Michael Basler
2 years ago
Im ha the same issue but with a wood stove in the basement and a new wood insert upstairs. both have liners

Smoke in basement from upstairs fireplace

Comments (5)

mpinto

berlin

Related Discussions

mjolson5
Original Author

berlin

Michael Basler

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

Smoke in basement from upstairs fireplace

Comments (5)

mpinto

berlin

Related Discussions

mjolson5Original Author

berlin

Michael Basler

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

mjolson5
Original Author