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  1. leoibb

    leoibb Member

    Joined:
    Dec 29, 2010
    Messages:
    84
    Loc:
    uk
    wow i cleaned the flue pipe. the flue pipe travels up through a masonry chimney and ive never closed the top of it so there was a gap all the way down the side of the flue pipe looking down from the top of the chimney. anyway i cleaned the flue pipe and what a mess came out and lots of it too i am very surprised. i am closing the gap round the flue pipe but am considering insulating it too. now is there any real benefits doing this, some say burns more efficient ?? back to the flue the fire draws tons better amazing.

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  2. KaptJaq

    KaptJaq Minister of Fire

    Joined:
    Jan 31, 2011
    Messages:
    703
    Loc:
    Long Island, NY

    If you have a lot of buildup in your flue it can be one or more of a number of factors. With the space around your liner and no cap you were letting cool air cool the pipe. When the smoke hits the cool pipe the creosote condenses on the pipe and builds up. Next factor is the smoke. Burning marginal wood causes more smoke than well seasoned wood, also a cause of more creosote. Is it an external or internal chimney? Do you have a block-off plate at the bottom? If it is internal I would put a block-off plate at the bottom, insulate the pipe above the roof line, and put a full cap on top. If external then I would also insulate the full length of the pipe.

    KaptJaq
    Backwoods Savage likes this.
  3. leoibb

    leoibb Member

    Joined:
    Dec 29, 2010
    Messages:
    84
    Loc:
    uk
    thankyou, es it is internal . i do have it blocked off at the bottom but never did at the top i went up to clean and was reminded lol. something i need to do but before i do what can i pour down the hole. i know of vermiculite but wont that be so messy if i change the pipe. so any options? what bout fibreglass wool? or is the temps too high for it?
  4. KaptJaq

    KaptJaq Minister of Fire

    Joined:
    Jan 31, 2011
    Messages:
    703
    Loc:
    Long Island, NY
    A lot of guys here use mineral wool, a brand name is Roxul, it can take the heat around the flue. If it is internal just pack Roxul around the liner at the top as far down as you can go (hopefully up to the roof line). When the air is trapped in the space between the blockoff plate and the top insulation/cap it will act as an insulator and keep the pipe warm.

    KaptJaq
  5. Backwoods Savage

    Backwoods Savage Minister of Fire

    Joined:
    Feb 14, 2007
    Messages:
    27,815
    Loc:
    Michigan
    Insulating should make a big difference.
  6. chimneylinerjames

    chimneylinerjames Feeling the Heat

    Joined:
    Nov 26, 2012
    Messages:
    381
    When you insulate the flue liner, you will have stronger draft right from the start all the way until there are just a few remaining coals left. As other have mentioned this will reduce creosote substantially. It is best to install insulation the entire length of the chimney, the results will be worth it.
  7. NextEndeavor

    NextEndeavor Burning Hunk

    Joined:
    Jan 16, 2011
    Messages:
    244
    Loc:
    Southern Iowa
    Double ditto. Insulate, makes a huge difference
  8. leoibb

    leoibb Member

    Joined:
    Dec 29, 2010
    Messages:
    84
    Loc:
    uk
    thanks for that chaps
  9. Kevin Dolan

    Kevin Dolan Burning Hunk

    Joined:
    Apr 7, 2012
    Messages:
    201
    Loc:
    SW Ontario
    So do you just go up to the cap on the chimney and stuff roxul down as far as it will go to insulate? Or use a pour type to get down the chimney? I have an external chimney about 20 ft high made of double brick with a stainless liner.
    Kevin
  10. leoibb

    leoibb Member

    Joined:
    Dec 29, 2010
    Messages:
    84
    Loc:
    uk
    hi i have just done mine . it was wide open, i just shoved fibreglass insulation down a foot softly, if it compresses it looses its u value, cemented it up and wow the stove is a lot better glass is clear and draw is great,
  11. KaptJaq

    KaptJaq Minister of Fire

    Joined:
    Jan 31, 2011
    Messages:
    703
    Loc:
    Long Island, NY
    On an external flue it is better to insulate all the way. Mine was internal.

    Roxul is like fiberglass bats just made from high temp mineral wool. I used bailing wire to make a cage, a length of wire in opposite corners then, a little below roof level, some cross pieces to keep the Roxul from falling. If yours is snug enough you probably do not need the cage. Slid the Roxul down around the liner loosely to just below the roof line then packed some tight near the top. In your case you might want to try to slide the bats all the way down using a long rod to push it or pour in vermiculite (a mess if you ever need to change the liner). Put a stainless cap over the top of the tile and sealed it with hi-temp silicon. The high-temp was overkill, the pipe never gets very hot up there. The sealing is important because it keeps the air from escaping.

    Vermiculite Kit: http://www.rockfordchimneysupply.com/insulation_kits.php

    KaptJaq
  12. etiger2007

    etiger2007 Minister of Fire

    Joined:
    Feb 8, 2012
    Messages:
    1,233
    Loc:
    Clio Michigan
    I plan on doing my external next summer, Im going to remove the top and pack it down as far as I can get with Roxul.
  13. corey21

    corey21 Minister of Fire

    Joined:
    Oct 28, 2010
    Messages:
    2,241
    Loc:
    Soutwest VA
    I think you should insulate it also.

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