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  1. #1
    Join Date
    Dec 2008
    Posts
    1

    Default Smoke in Basement

    We have a 1973 home that has two wood burning fireplaces. We sealed the lower fireplace at the top because the basement was not finished. We used the upper fireplace and it worked great. We now have a finished basement and I had a chimney sweep come out and open the lower fireplace. Both fireplaces have top dampers. Problem is we get smoke in lower room through lower fireplace. I originally thought it was a negative pressure situation but had an HVAC guy install 6 inch cold air intake. Doesnt seem to help. I have tried opening windows on both and either level. Doesnt seem to help. Advice would be great. I am new to posting.

  2. #2
    Join Date
    Jan 2008
    Posts
    731

    Default Re: Smoke in Basement

    Quote Originally Posted by townie View Post
    We have a 1973 home that has two wood burning fireplaces. We sealed the lower fireplace at the top because the basement was not finished. We used the upper fireplace and it worked great. We now have a finished basement and I had a chimney sweep come out and open the lower fireplace. Both fireplaces have top dampers. Problem is we get smoke in lower room through lower fireplace. I originally thought it was a negative pressure situation but had an HVAC guy install 6 inch cold air intake. Doesnt seem to help. I have tried opening windows on both and either level. Doesnt seem to help. Advice would be great. I am new to posting.
    call the chimney sweep back. you paid to "open" clean and inspect and make it ready for use should have tested draft and now you're having problems. either missed something or didn't do job or something has happened like a critter nest in the flue or on the cap for example. if missed something should correct/fix and the return visit portion should be no charge.

  3. #3
    Join Date
    Aug 2007
    Posts
    612

    Default Re: Smoke in Basement

    Do I understand correctly? You are getting smoke coming out the lower fireplace when you have a fire in the upper fireplace? And this happens when the top damper is closed on the lower fireplace?

    This did not happen when you had sealed the lower fireplace at the top of the chimney? Is this an exterior chimney?

    If I understand correctly, it sounds like the top damper of the lower fireplace is not sealing and you are getting a downdraft that is sucking the smoke from the upper fireplace down the chimney. Do you have any trouble with smoke in the basement when starting a fire in the lower fireplace?

  4. #4
    Join Date
    Aug 2007
    Location
    The Great White North
    Posts
    4,045

    Default Re: Smoke in Basement

    townie .... welcome to the forum.

    If I understand correctly you are having smoke backing up from the fireplace in the basement while trying to use it?

    It seems you have tried to address one of the more common issues of not enough make up air.

    As bp21901 mentioned if the flues running inside the chimney are located on the exterior they will be colder than those running through the interior.

    Perhaps your flue needs to be primed first. A simple thing to try .... roll up some newspaper and light it. Hold this up inside the firebox .... the smoke from the lit newspaper should start to go up as the air inside warms.
    Once this happens try lighting a fire to see if it draws ... if it doesn't there are other issues.

    You mentioned this fireplace was down in an unfinished basement for awhile.
    It's unclear if this was a rough in which case it may have been intended to have an insert or glass doors installed ..... or was it always a finished fireplace ?

    If the size of the opening of the fireplace is too large could restrict the exhaust from combustion. The amount of air entering the fireplace must correspond to the amount of air that can exit from the flue. More air entering than is allowed to exit can create a bottleneck not allowing a nice steady convection air flow.

    You might also try raising the fire with some bricks or a taller grate to see if this improves the situation.

    If this doesn't help it may be the opening might need to be reduced.
    Short of rebuilding the firebox or adding an insert ...... a smoke guard might help since it will reduce the opening or glass doors might need to be installed.

    Perhaps it would have been a good idea to have tested this fireplace when the chimney was being opened. You may need to have a professional experienced with fireplaces to evaluate things if priming and/or raising the fire doesn't improve things.

    Just a thought.
    "" an ounce of perception -- a pound of obscure "
    - Rush

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