1. Welcome Hearth.com Guests and Visitors - Please enjoy our forums!
    Hearth.com GOLD Sponsors who help bring the site content to you:
    Hearthstone Soapstone and Cast-Iron stoves( Wood, Gas or Pellet Stoves and Inserts)
    Caluwe - Passion for Fire and Water ( Pellet and Wood Hydronic and Space Heating)

Class A Install: which installer is "right?"

Post in 'The Hearth Room - Wood Stoves and Fireplaces' started by Charles Bourque, May 23, 2013.

  1. Charles Bourque

    Charles Bourque New Member

    Joined:
    Feb 13, 2013
    Messages:
    8
    Talked to two guys who install class A chimneys. One guy says, "the ceiling support box has to extend 18" below the ceiling." The other guy says, "nah, since you're only going through 1' of attic, just use a
    24" ceiling support, put it 3" below ceiling, let the top of it out through roof, screw it in to framing, then cut the excess above roof in several places and nail down the flaps." Second guy says that eliminates need for attic insulation shield.

    Who's righter? Second guy makes me nervous, but if he's right, I like his approach.

    Helpful Sponsor Ads!





  2. webby3650

    webby3650 Minister of Fire

    Joined:
    Sep 2, 2008
    Messages:
    3,667
    Loc:
    southern Indiana
    The second guy is right. Most manufacturers require the box to extend only a few inches into the room. The amount changes only changes if it's a cathedral ceiling, the steeper the ceiling, the farther the box needs to extend into the room.
  3. Holiday

    Holiday Member

    Joined:
    Feb 18, 2013
    Messages:
    172
    Loc:
    Saskatchewan, Canada
    My install manual says 3" below the ceiling.
  4. Delta-T

    Delta-T Minister of Fire

    Joined:
    Feb 27, 2008
    Messages:
    3,097
    Loc:
    NH
    i bet there are some differences between manufacturers...I'd reference the particular manufacturers literature.
    DAKSY likes this.
  5. webby3650

    webby3650 Minister of Fire

    Joined:
    Sep 2, 2008
    Messages:
    3,667
    Loc:
    southern Indiana
    There is a little difference, but it's never 18"! This shows a lack of experience on the part of the potential installer. He think the stovepipe needs to be 18" from the ceiling measured vertically. Thats incorrect.
    BoilerMan likes this.
  6. webby3650

    webby3650 Minister of Fire

    Joined:
    Sep 2, 2008
    Messages:
    3,667
    Loc:
    southern Indiana
    Above all, this is the most important.
    BoilerMan likes this.

Share This Page