(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 5 of 5

Thread: Decommissioning a flue

  1. #1
    In the trades Dana's Avatar
    Join Date
    Jan 2009
    Location
    01609
    Posts
    2,714

    Default Decommissioning a flue

    My newer gas fired heat/hot water system is side vented, and I've been pondering what's the best/right/legal option for decommissioning the flue.

    This is a circa 1923 red brick chimney with two separate terra cotta lined flues, one for a (not-much-used but functional) wood burning fireplace, the other formerly used for a gas fired boiler & hot water heater, the latter of which is now not use. It's an air infiltration source, and it leaks a tiny bit rainwater into the basement in super-downpours, so I'm thinkin' I should probably do something with it at some point...

    Can I just brick it up at the bottom and cap it a the top? (Plan-A)

    Do I need to/want to fblow it full of rock wool (at least up to the roof line), since it's on an exterior wall, then brick & cap it? (Plan-B)

    Should I just cap it & fuggedaboutit? (Plan-C)

    Or should I do something else?

  2. #2
    Senior Robin Hood Guy Ian Gills's Avatar
    Join Date
    Jul 2007
    Location
    USA
    Posts
    2,781

    Default

    I would always install a chimney cap on any chimney.

  3. #3
    Moderator & Master Plumber hj's Avatar
    Join Date
    Aug 2004
    Location
    Cave Creek, Arizona
    Posts
    25,605

    Default chimney

    Put a chimney cap on them to keep the rainwater out, then seal the openings into them to prevent drafts.

  4. #4
    In the trades Dana's Avatar
    Join Date
    Jan 2009
    Location
    01609
    Posts
    2,714

    Default

    Quote Originally Posted by Ian Gills View Post
    I would always install a chimney cap on any chimney.
    However, in this case I'm talking about a ceramic or cement-board cap that seals it at the top, not just a rain-hat for the flue to keep the drips out...

  5. #5
    DIY Senior Member burleymike's Avatar
    Join Date
    Nov 2008
    Location
    Idaho
    Posts
    118

    Default

    If the masonry is in good shape you can just get some galvanized flashing and use silicone to glue it over the top of the liner opening. That way no more air/water will enter and it will keep cats out. You can seal it up the same way in the basement. You should have the flashing hang over the sides of the liner 1/4"-1/2" to direct water away from the liner.

    That is what I did on mine. I plan to use that chimney in the future for a wood stove. It is in super good shape for being 50 years old. The liner still looks new. I actually found a barn cat in the basement. There was some hair stuck around the chimney opening, so I knew that was how he got in.
    Last edited by burleymike; 12-07-2009 at 11:22 AM.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •