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)

Making a Fireplace Damper Cut-Off Plate

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by smwilliamson, May 28, 2013.

  1. smwilliamson

    smwilliamson Minister of Fire

    Joined:
    Dec 28, 2009
    Messages:
    3,888
    Loc:
    Southcoast, MA
    Made my first video today on the iPhone. Here is how I make my fireplace damper terminations. What I forgot to mention...there is 8" of mineral wool on top of these plates.

    For those who are curious...yes, that's me there doing the talking. MY GOD! I'm bald!!




    mepellet, mralias and Defiant like this.

    Helpful Sponsor Ads!





  2. Defiant

    Defiant Vermont Castings Geek

    Joined:
    Dec 5, 2007
    Messages:
    2,112
    Loc:
    Old Lyme CT
    Nice job, made many in my time, always seemed to get cut;)
  3. DexterDay

    DexterDay Guest

    Well done... Kill the fly!! LOL
    mepellet likes this.
  4. Ram 1500 with an axe...

    Ram 1500 with an axe... Minister of Fire

    Joined:
    Mar 26, 2013
    Messages:
    1,685
    Loc:
    New Jersey
    Great job!!! And don't worry, GOD is with you my man....
  5. Don2222

    Don2222 Minister of Fire

    Joined:
    Feb 1, 2010
    Messages:
    6,836
    Loc:
    Salem NH
    Nice Video of damper plate with insulation.

    8" of Roxul is R32 ! ! ! That keeps the cold out!

    Is that what is in there?
  6. mralias

    mralias Minister of Fire

    Joined:
    Apr 29, 2008
    Messages:
    863
    Loc:
    MA
    Am I assuming correctly that the purpose of this block off plate is so you don't have to run the liner all the way to the top of the chimney? i.e "fireplace damper terminations" Or am I dead wrong and if so why? I had the same set up on my woodstove install prior to the pellet stove so that is sort of why I am asking.
  7. smwilliamson

    smwilliamson Minister of Fire

    Joined:
    Dec 28, 2009
    Messages:
    3,888
    Loc:
    Southcoast, MA
    Ah, good question. No, in fact my liner here goes all the way to the top of the chimney...about 31' up there. It was a high one. The purpose for the cut off plate is to seal off the warm air from the house and keep it from rising up into a cold chimney cavity.

    Not as Don mentions...to keep out cold drafts, though it does help with that too.

    What you are talking about is what we call a damper installation. They are not allowed in MA. They should be banned anyway as they are problematic on for many reasons. Very much a PITA to clean and maintain...especially when they have been neglected for 11 years or so.

    Difference being, with a pellet stove, the exhaust motor drags a lot of ash from the stove into the venting and it just piles up high on the other side of the plate. Wood, not so much...though there is some.
    Defiant likes this.
  8. Defiant

    Defiant Vermont Castings Geek

    Joined:
    Dec 5, 2007
    Messages:
    2,112
    Loc:
    Old Lyme CT
    Damper installs are still allowed in CT with a 6' stainless flex kit, I do prefer and recommend all the way up sealing off at the top.
  9. Don2222

    Don2222 Minister of Fire

    Joined:
    Feb 1, 2010
    Messages:
    6,836
    Loc:
    Salem NH
    Hello
    The metal damper seals the chimney and keeps the warm room air from rising out. I was talking about the insulation which keeps cold from convecting in thru the metal. :) Also if the insulation is fire proof it will protect the room against a chimney fire !
  10. mralias

    mralias Minister of Fire

    Joined:
    Apr 29, 2008
    Messages:
    863
    Loc:
    MA
    Ah, very nice explanation. That helps me a lot thanks. Looks like I will be making one of those bad boys for my insert. What about the OAK which is a different 2" line that goes to the top? Would you cut two holes in the plate?
  11. Delta-T

    Delta-T Minister of Fire

    Joined:
    Feb 27, 2008
    Messages:
    3,097
    Loc:
    NH
    i dunno...what kind of technician bends over and doesn't show some "cleavage"? You're gonna make the rest of us look bad ;lol. Nice snipper work. We use a fancy plasma cutter thingy. HIgher danger level=more danger. And who doesn't like some danger?
    jtakeman likes this.
  12. Don2222

    Don2222 Minister of Fire

    Joined:
    Feb 1, 2010
    Messages:
    6,836
    Loc:
    Salem NH
    Hello

    Here is a good video on how to insulate a chimney liner with a spray adhesive. This is what Olympia Chimney was talking about. It works well for chimneys on the end of a house that are cold outside chimneys. The insulation keeps the flue gasses from cooling too quickly and the ash collecting and building up on cold spots on the inside walls that can choke the chimney down quickly in some cases. Nice extra benefit.

    http://www.youtube.com/watch?NR=1&v=5OIcxRdb6Rs&feature=endscreen

  13. smwilliamson

    smwilliamson Minister of Fire

    Joined:
    Dec 28, 2009
    Messages:
    3,888
    Loc:
    Southcoast, MA
    Yes, if the outside air is going to be taken from the chimney flue you would make another section. When I do those, I make my plate into 3 sections and take the air up the other side. If you are taking the air line up like that you also need a different type of cap. It's called a collinear cap. I use this one from Olympia. They make them in crown mount and terra-cotta mount. You have to specifiy that you want a 3" adapter for the air supply line, they come 4" and 4" for exhaust and air.
    [​IMG]

    http://www.olympiachimney.com/products/cat/CC/ASCC/CCCLTM
    mralias likes this.
  14. smwilliamson

    smwilliamson Minister of Fire

    Joined:
    Dec 28, 2009
    Messages:
    3,888
    Loc:
    Southcoast, MA
    You don't really know what you are talking about do you?
  15. smwilliamson

    smwilliamson Minister of Fire

    Joined:
    Dec 28, 2009
    Messages:
    3,888
    Loc:
    Southcoast, MA
    I understand...but once again you are displaying a wood stove liner and not a pellet liner. You are displaying what is needed for a natural drafting wood stove liner. THIS IS THE PELLET FORUM DUDE!
  16. Don2222

    Don2222 Minister of Fire

    Joined:
    Feb 1, 2010
    Messages:
    6,836
    Loc:
    Salem NH
    Olympia liners work for wood and wood pellet stoves, boilers etc. Chimneys are different, center chimney, outside chimney. Olympia talks about the right liner for the type of chimney not the appliance!
  17. Don2222

    Don2222 Minister of Fire

    Joined:
    Feb 1, 2010
    Messages:
    6,836
    Loc:
    Salem NH
    The metal damper and caulking seals the chimney and keeps the warm room air from rising out. I was talking about the insulation added above the damper which keeps cold from convecting in thru the metal. :) Also if the insulation is fire proof it will protect the room against a chimney fire !

    I am not saying anything was done wrong, just helping to provide more info so the best choices can always be made.

    Then if this is not the case, you explain it better?
  18. smwilliamson

    smwilliamson Minister of Fire

    Joined:
    Dec 28, 2009
    Messages:
    3,888
    Loc:
    Southcoast, MA
    I am stuck on pellet stoves because this is the pellet forum;) and the name of my company is pellet stove service.!!!
    The purpose for the damper plate:
    1. To keep warm air from rising up in to the chimney. Warm air contains moisture. The moisture will condense in to chimney and be absorbed by the masonry. When temps fall below freezing the water in the masonry will expand and over time the chimney will start to fall apart.
    2. If you have a multi-flue chimney, such as the case with this install, if the OTHER chimney flue ever had a fire....the flue we are in could supply air to that fire.
    3. I suppose insulating the chimney damper can keep out cold drafts...but there is presumably a stove in the opening which is on and thus cold air isn't going to be felt. The flue is also capped at the top so we aren't talking about air rushing down the flue.
    Insulating the liner...with pellet liners it is not required and would not really contribute to the drafting. Wood stoves or should I say, NATURAL drafting appliances...and there are pellet stoves that utilize natural draft, would and do benefit from insulated liners. I'm not the be all end all when it comes to this type of work but you are confusing people by showing the installation of a 6" wood stove liner. FYI I didn't see those guys install a damper plate on that Jotul.
  19. Don2222

    Don2222 Minister of Fire

    Joined:
    Feb 1, 2010
    Messages:
    6,836
    Loc:
    Salem NH
    Hello

    From the Pro liner venting catalog:

    Why and When to insulate the chimney liner:

    click to enlarge:

    [​IMG]

    Attached Files:

  20. smwilliamson

    smwilliamson Minister of Fire

    Joined:
    Dec 28, 2009
    Messages:
    3,888
    Loc:
    Southcoast, MA
    We could go back and forth forever. If you want to wrap your pellet liners, there isn't really a downside. Knock yourself out. Is it really needed? No. Will it hurt? No. Will there be any problems if you don't? No.

    If you do not agree, find some liners not insulated and show us evidence. I'm willing to bet I have installed more inserts alone than stoves you have looked at seen or worked on. I go back to these inserts year after year after year and there is NO evidence of creosote whatsoever anywhere in the liner. We are talking hundreds of inserts a year man....if there was going to be a problem I would have seen it by now.

    But then again you may be just the man for the job. Like I said, knock yourself out.
  21. Don2222

    Don2222 Minister of Fire

    Joined:
    Feb 1, 2010
    Messages:
    6,836
    Loc:
    Salem NH
    I agree. The chimney suppliers are always trying to sell more stuff.
  22. smwilliamson

    smwilliamson Minister of Fire

    Joined:
    Dec 28, 2009
    Messages:
    3,888
    Loc:
    Southcoast, MA
    I will toss it out there though..there are situations where insulating the liner is needed.

    If I am installing a liner on an outside facing chimney that is higher than 45 feet...I will insulate.
    If I am installing in a chimney that does not have a clay lining in the flue...I will insulate.
    If I am installing in a chimney with an off-set...I will insulate.
    If I am installing in a chimney where the clay flue tile is damaged or missing in sections...I will insulate.

    The first is a performance issue, the rest are safety issues.

    Maybe 1 in a hundred installations fall in to these categories.

    DONE with this thread unless there is something new to add:)

Share This Page