New guy with a hearth question

Mbgame Posted By Mbgame, Jul 14, 2008 at 3:28 PM

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  1. Mbgame

    Mbgame
    New Member

    Jul 14, 2008
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    Loc:
    Enfield Ct
    I have a Harman Accentra pellet stove on the way to be installed in a few months and I was wondering if it was possible to make a hearth pad by using concrete. The pad would be going over the top of the existing hardwood floors and be 4 inches thick. I was thinking about making it following concrete counter top instructions and installing molding in the form box to give it a little bit of detail along with black dye to get it to resemble cast iron as much as possible. After reading a few articles on R-values and other construction ideas I wasn't sure if just plain concrete would cut it. Any feedback on my idea would be great. Thanks
     
  2. begreen

    begreen
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    Nov 18, 2005
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    As long as it meets the hearth size requirements this should be no problem. Like many pellet stoves, the Accentra has very minimal hearth requirements.
     
  3. Drivr

    Drivr
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    Jun 7, 2008
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    Loc:
    Seacoast, NH
    I'm guessing your never going to move this pad. a concrete pad say 4 ft square and 4 inched thick is going to weigh in the neighborhood of 710Lbs. But I bet it would look nice.

    Double checked my math, 4x4x.3=4.8(cubic ft), 4.8x148=710.4. from what I remember 1 cubic foot of concrete with Portland cement weighs around 148 pounds. Make that pad 3 inched thick instead and use fibered concrete for support and it will weigh only 592 pounds instead of 710 pounds.
     
  4. hoverfly

    hoverfly
    Minister of Fire

    Jun 26, 2008
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    Here is a lighter, version 3/4" ply wood, at least 3/8" thick tiles and between the tiles and ply 1/2 cement board, this one is optional. Or 3/4" ply build around a raised border and fill it with cement.
     
  5. hoverfly

    hoverfly
    Minister of Fire

    Jun 26, 2008
    550
    17
    Loc:
    Southern NH
    Here is a lighter, version 3/4" ply wood, at least 3/8" thick tiles, between the tiles and ply 1/2 cement board, this one is optional. Or 3/4" ply build around a raised border and fill it with cement.
     
  6. Mbgame

    Mbgame
    New Member

    Jul 14, 2008
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    Loc:
    Enfield Ct
    [​IMG]

    This is the shape and rough size of the hearth idea. After reading the post about the weight I plan on reducing it down to 3 inches thick. With those measurements using fiber reinforced concrete it should weigh 340lbs if I did the math right. It should span 4 floor joists with the back of the stove next to a load bearing wall. With the stove the total weight should be 710lbs. I'm pretty sure the floor can handle it, the other end of the room has an aquarium that totals out at around 1400lbs and covers 3 joists with a load bearing wall in back of it. I hope it supports it anyway! Once again though any hints, tips or ideas are more than welcome.
     
  7. johnnywarm

    johnnywarm
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    Sep 12, 2007
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    Support the floor before you go forward.
     
  8. slls

    slls
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    Jun 9, 2008
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    All you need is a non combustible surface. Out of the Harmon manual, 20 gauge sheet steel will be sufficient. Just an idea of what is required, you can go up from there. Here is mine, ceramic tile on ply wood.

    [​IMG]
     
  9. Drivr

    Drivr
    Member

    Jun 7, 2008
    43
    4
    Loc:
    Seacoast, NH
    Ive seen people use 6" thick solid concrete blocks for a pad under a wood stove and had no problems with the floor. your going to be spanning 4 floor joists I don't think you would have any problems with this. but then again I'm not a carpenter or an engineer.
     
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