Clearance confusion

[runituptop]

I am planning to install a Jotul F3 wood stove in front of my existing fireplace. Existing brick hearth pad area is being extended forward. I plan to have the stove sit as far back as possible toward the fireplace opening (but not in the firebox).

I have a few questions regarding clearances.
Note - the existing brick fireplace surround is 61" from side to side and is a couple of inches proud of the wall.

The F3 manual page 12 has information about clearances to mantel and trim. My fireplace surround and mantel is brick only, no wood trim or mantel.

a. Do I need to be concerned with the "top to trim" or "top to mantel" measurements since the trim is non-existent and the mantel is brick? The top row of brick extends out 7 inches. It seems to me that these clearances would then not apply?

b. Do I also ignore "side to trim" since there is no side trim other than brick surround?

c. The "side to side wall" measurement (D) - is that referring to a side wall that is perpendicular to the back wall, or is that referring to the back wall that is to either side of the fireplace/brick? And where does this measurement start - the rear corner of the stove? The center of the stove side? The centerline?

Thanks! This site has been very helpful to read.

 

[begreen]

Welcome runituptop. No, the clearances are to nearest combustibles. If everything surrounding the stove is brick, you should be fine. Post a picture if you want us to look for any issues.

 

[runituptop]

Thank you, begreen.
Do I need to be concerned at all with the distance between the rear corner of stove (or stove side) to where the combustible wall begins on the rear wall (in other words, a diagonal measurement from stove to rear wall next to the brick surround?)
I can try to post a picture later when I have access.

 

[fossil]

Sounds to me as though the only clearance you need concern yourself with is from the front of the stove window. If your existing hearth is deep enough, you're golden all around. Rick

 

[runituptop]

Thanks, fossil. That is what I am hoping!

After poking around this site, I've got a decent plan (I think) for extending the hearth pad area in front. Existing brick hearth area is 1" higher than the surrounding subfloor. So the plan is to cut away the carpet, build up 2 layers of 1/2" Micore 300 to be flush with the existing brick area (which give me R value >2, and I only need around 1.1); then cover the entire area (brick and micore) with 1/4" cement board wrapped in sheet metal. I do not want to tile over it. Trim it out with an oak border, and refinish the carpet edge to the oak.

From what I've seen, the cement board (that will be wrapped) will need to be Durock or Hardi to maintain the non-combustible requirement there.
See any issues with that? Would love to correct any problems before I get started.

Thanks!

 

[begreen]

I dont think you want to do that. Micore is soft. Instead, skip the Micore and use Durock Next Gen for your 1" build up, then 1/4" on top of brick and . After that you lost me. Are you planning on having raw cement board as the top layer? That would be a bit crude. And why the sheet metal wrap? Or is that the top layer? Galvanized sheet metal doesn't sound too attractive for a top layer, but it would serve the function I guess.

 

[runituptop]

I was questioning how soft the Micore is. On one hand, I don't think it will matter much because the stove legs will not be resting over that portion of the pad extension, so it will not have much weight on it, if any. But, since I have to make up 1" to be flush with the existing brick, I could go 1/2" Micore and 1/2" Durock - that would give me the increased R value from the Micore and some added strength from a Durock layer.

That would create a hearth area that is partially brick (existing hearth pad) and partially Micore/Durock - all of it 1" higher than surrounding subfloor. I want to keep the overall height as low as possible while creating a consistent surface, so I would then lay another piece of 1/4" Durock to cover that whole area, but it will be wrapped in steel, so the metal is the outer/visible layer. You won't see any cement board. Metal will be painted black w/ high temp paint. We had a similar pad when I was a kid, and it looked good. That gives me a solid surface with no seams, non-combustible, durable, and thin profile.

 

[begreen]

Got it, my only concern then is with the 1/4" Durock top layer. I think I would prefer to have 1/2" under the metal and stove.

 

[runituptop]

Thanks, begreen. Agreed. Still going back and forth on that one - 1/4" vs 1/2". I am really tempted to keep it as low profile as possible. Do you think I could get away with the 1/4" top layer if the build-up layer below it had the 1/2" Durock instead of 1/2" Micore (mentioned above)?

 

[begreen]

It's the weight of the stove legs on the metal that has me a little concerned. If the metal is not heavy enough I think it might dimple the metal and crack the durock. This wouldn't be a big safety issue, it's more cosmetic.

 

[runituptop]

What do you think about using 1/4" steel plate instead? I thought it may get too hot, so I was going with the wrap for the top layer. I think the wrapped Durock will reflect and dissipate heat better.

 

[begreen]

18 or 20 ga should be stout enough. Don't worry about the heat, it will dissipate and durock is non-combustible.

 

[skinanbones]

In these situations with customers that want to use steel we tend to use 3/16 or 1/4. In your case i would recommend using the 1/4 as it would finish at your brick height and give you something that is strong and sturdy. If you want to go all out you could weld an edge to it that would cover the 1" build up and rest on the carpet holding it in place and finishing it off without using trim

 

[joecool85]

In these situations with customers that want to use steel we tend to use 3/16 or 1/4. In your case i would recommend using the 1/4 as it would finish at your brick height and give you something that is strong and sturdy. If you want to go all out you could weld an edge to it that would cover the 1" build up and rest on the carpet holding it in place and finishing it off without using trim

This is what I would do.