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Chimney pipe is through the wall.....but

Post in 'The Hearth Room - Wood Stoves and Fireplaces' started by jstellfox, Sep 19, 2010.

  1. jstellfox

    jstellfox New Member

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    due to the nature of my install (through a block NON-combustible wall with supervent pipe) we will not be using a thimble as it is optional for a non combustible wall with supervent. My horizontal section through the wall will be disconnected when I clean the flue so I don't want to mortar my chimney pipe to fill the small gap between my wall hole and the chimney pipe. Is there any type of fire proof insulation that can be used to fill the void around the pipe that I could just remove and re-install when I need to clean the flue? This is a wood stove application

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  2. jstellfox

    jstellfox New Member

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    Sorry to bump, but would really like some suggestions. I found some 1000 degree rated pipe wrap insulation that should work for chimney pipe. Double wall chimney pipe is supposed to be cool to the touch so i would assume that sticking some if this insulation around the horizontal piece through my block basement wall to seal any gaps would be ok? Anyone else put any kind of insulation around their stainless steel chimney pipe through the wall?
  3. begreen

    begreen Mooderator Staff Member

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    Is this 6" round pipe? If yes, maybe make a sleeve of 8" round stainless? Otherwise, it this is just draft prevention, I would think some kaowool would work ok.
  4. jstellfox

    jstellfox New Member

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    Yes the pipe is 6" stainless steel double wall insulated chimney pipe. Where the pipe goes through the concrete block there is a 1/2" gap the whole way around the pipe that needs filled in so the outside air is not able to leak into my basement. I am just looking for options to fill in the gap around the pipe other than filling with mortar and hoped that I could just use some type of insulation to stuff in the gap...
  5. vvvv

    vvvv New Member

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    1 reason for 2" clearance around class a is that the exterior insulated pipe has a zone which can overheat due to the constricted airspace. i'd insulate/plug on interior & exterior of wall & leave most of the pipe within the wall uninsulated, + add collars
  6. jstellfox

    jstellfox New Member

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    fiberglass insulation doesn't burn, so is it safe to plug the gaps around the pipe with regular fiberglass insulation? And by plus I don't mean wrapping the entire horizontal pipe section, just plugging the gap between the pipe and wall on the inside and outside. Anyone care to chime in?
  7. DAKSY

    DAKSY Patriot Guard Rider Staff Member

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    Averill Park, NY, on Burden Lake II...
    That's what I would do. Take the Kraft facing off & jam it in from the inside
    & outside & add trim collars RTV siliconed in place.
    Our company has been insulating SS chimney liners & Class A thru masonry with fiberglass
    for 33 years & we have not had one instance of a problem.
    Fiberglass does not melt. It does not burn & it does not outgas at woodburning temperatures
    Others in here will EMPHATICALLY disagree with the idea of doing this,
    & I'm willing to bet NONE of them have the time in this industry that we do.
    Use the fiberglass & you will be fine.
  8. KevinG

    KevinG Member

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    Lancaster County, PA
    I'm planning to do something very similar in my house. But I need to go through a triple-brick wall. How did you make the round 8" hole?

    I've heard that a core drill would do a nice job. But haven't found a local place that rents them yet.
  9. jstellfox

    jstellfox New Member

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    well we started with a hammer drill and found out that getting a drill bit through terracotta block is not easy at all. It worked out better for us to chisel out the whole block. The pipe fits through the removed block hole and we are going to mortar around the pipe leaving a gap and then stuffing the gap with insulation...its the best we could come up with

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