DIY Fire Wall/Shield for Fisher Stove

FarmDog Posted By FarmDog, Jul 23, 2013 at 11:02 AM

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  1. FarmDog

    FarmDog
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    Jul 23, 2013
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    This is my first post, though I've read through the tons of great information on this forum, including many posts about firewalls and shields. Still...I'm confused.

    I bought an old Fisher stove at an auction last year for $300...then spent MUCH MORE than that on the pipe and installation (see pic). [​IMG]

    I'm in Georgia so I haven't had a chance to use it other than test firing it late last winter...boy does it CRANK the heat! Right now, I have it sitting on a solid piece of granite above a wood floor, but plan on covering the wood floor with tile, cement board and OSB, as it got VERY hot behind and below the stove.

    To the left of the stove is a stone wall, so I'm not worried about that. To the right is drywall and that's what I think I should be concerned about...but I'm not sure. The stove is 26" from the drywall and from the stone. In the rear, I've built a half way that is 31" away from the stone, and 20" away from the rear of the 8" pipe.

    My questions are:

    1. Do I need a fire shield at all on the drywall?
    2. If so, can I just put tile on cement board and mount that to the wall studs, or do I still need to create an air pocket behind that?
    3. Finally, would tile on cement board on OSB work for underneath the stove?

    Thanks for your help. We want to get off the electric grid, but we don't want to burn the house down!
     
  2. Jags

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    First - get the manual for that stove if possible. Clearance to combustibles is 36" all around unless otherwise stated. There is a difference between a non-combustible wall and a heat shield. A heat shield must be spaced away from the wall and designed for air to enter from the bottom and sides of the shield. Heat shields can change the clearance specs, but not all stoves are the same, so I will not venture a guess at how much this will help you.

    I will leave this in the hearth room (at least for now) because this is more of an install question than a stove question and this will get more reviews here.

    And welcome to the forum.

    ETA: You really need to know the specs for the floor, too. Ember protection? R value? These are the unknowns that need to be answered.

    You may want to review this:
    http://www.hearth.com/talk/threads/fisher-papa-mama-and-baby-bear-details-bear-series.86736/

    and member Coaly is a great resource for Fisher info. You may want to start a conversation with him.

    I found it:
    http://hearth.com/images/uploads/Fisher_Manual.pdf
     
  3. begreen

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    Calling coaly to the front desk. Fisher specs needs on aisle 4.

    Moved to the classics forum to catch the Fishermeister's attention. Maybe coaly has the manual? As jags has pointed out, you need to make sure your floor is properly protected as well as the walls. By the description, it sounds like you may need a couple layers of 1/2" Durock nexgen cementboard on top of 3/4" plywood, then tile to provide that, but we need a spec for the stove to be sure.

    Here's an article on wall shielding.
    http://www.hearth.com/econtent/index.php/articles/stove_wall_clear
     
  4. Jags

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    Good call BG - I was reconsidering it myself. Manual is posted at the end of my first post.
     
  5. begreen

    begreen
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    Ah, great, thanks. Looks like the stove is calling for millboard. For peace of mind I would make up a hearth pad as I specced, a couple layers of 1/2" Durock nexgen cementboard on top of 3/4" plywood, then tile. Or you could use a single layer of 1/2" Durock nexgen and a layer of brick on top of that.
     
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  6. FarmDog

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    Reading the manual now (thanks). So, if the clearance to combustibles is 36" and I have two combustible walls within 36", the question I have is what options do I have to make them non-combustible? Going back to my question above, can I just put tile on cement board and mount that straight on the drywall, or do I still need to create an air pocket behind that? According to this (http://www.hearth.com/econtent/index.php/articles/stove_wall_clear), it looks like I need to allow airflow, but my local installer (who did the pipe) said it wasn't necessary. Hence my confusion.
     
  7. Jags

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    Non-combustible is measured to the nearest "combustible", meaning wall studs, paper on drywall, etc. Putting tile over drywall doesn't move that drywall or wood studs any further away. You will be interested in a heat shield and YES, this needs to allow for air motion behind it.

    This will make a difference in clearance specs for sure, but I don't recall if the Fisher manual recites the specs or not.
     
  8. begreen

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    Your installer is incorrect. You need to provide a 1" air space behind the cement board and at least 1" open at the bottom and top to allow unrestricted ventilation behind it. No big deal really. Just make some long 3" strips from the end of cement board. Then double them up to make 1" thick shims and screw them to the studs. Then mount the cement board onto the shims, 1" off of the floor.
     
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  9. Jags

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    For a change up in looks...copper, tin, stainless, etc. could also be used.
     
  10. FarmDog

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    Great idea...thanks. So, if I leave a 1" space on the bottom as well, do I need to take off the baseboard or can I just leave it on?
     
  11. Jags

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    If it is a combustible, it must be taken into consideration. That said - a 1" gap at the floor will probably not allow for the baseboard to be subjected to vast amounts of heat. I know - I didn't answer a thing.;)
     
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  12. FarmDog

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    :) Yeah, I figured, by my thinking is that if I leave 1" open from the bottom then clearly the bottom of the wall is exposed even if I take off the baseboard, and the wall is combustible. Oh well.
     
  13. DAKSY

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    I'd say remove the baseboard trim to ensure you meet the 1" air gap, otherwise you can move the heat shield to the 1" dim PLUS the thickness of the trim. 1" is minimum. More is better...Maybe not aesthetically desirable, tho...
     
  14. Osage

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    I used tin spaced 11/2" from wall on my install in my shed/cave. Seems that the reflective tin only gets warm to touch with the mama putting out more heat than is needed on a cold day.
     

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