Rear clearance to NON-combustibles?

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Badfish740

Minister of Fire
Oct 3, 2007
1,539
This may sound like a dumb question, but it has a good reason. I'm trying to engineer a hearth that doesn't overpower the room that it's going to be in-in other words, I don't want it and the stove to seem like the biggest things in the room. That being said I want to make it as compact as possible while being within code and safe. When browsing through stove manuals online, I constantly see the "clearance to combustibles" numbers everywhere, which I take to mean clearance to a conventional wall (drywall, paneling, plaster, etc...) which can readily burn. Is this correct? In other words, provided ample floor protection was provided in the form of non combustible materials, air gap, etc...could the stove be placed near a conventional combustible wall provided the stove sat the prescribed distance from said wall?

I ask this because the stoves I'm looking at have minimum rear clearances of anywhere from 8-10" from COMBUSTIBLES. However, if I were to build a hearth wall behind my stove consisting of existing drywall covered by 1/2" cement board, framed with steel 2x3 studs (which would provide a 2 1/2" air gap), faced with 1/2" cement board/brick veneer, would I still need to place my stove 8" from THAT wall? Or would it be considered safe to back the stove up to the wall with 1 or 2 inches of clearance? This is also assuming a double wall insulated chimney from the stove outlet to the roof as well. If I could place the stove closer to the wall I think that it would look much better in the room so I'm hoping that it's not only an option, but a safe option.
 
What stove is this? Most stove manuals give multiple clearance tables - one is usually for clearance from a shielded wall. That is the clearance you want to look at.

No need to overkill the wall shield. Make the first layer out of durock with two layers of 1/2" durock strips (3-4" wide) as the spacer shims. That will work fine as a shield and as a tile or stone veneer base.
 
Making an NFPA 211 compliant reduced clearance wall will allow you up to 12" from the combustibles behind that wall Making the space 2.5" will not allow you to reduce the 12" minimum any further. However should you find a stove with manufacturer's tested and listed specs less than 12" you may install it according to what is tested listed and approved

the only other way would be to make the wall behind it completely built with non combustibles including the sheathing siding and interior sheathing Even if you could place a stove that close Might I remind you, The stove needs air space for convection and heat dissipation.

there are two pieces of the clearance issue the stove location and the connector pipe heat shields and NFPA wall protection system can only reduce the single wall connector pipe to 12"
there is not code language to reduce it further If you use a double wall pipe then you use it clearance as listed usually 6" that 6" can not be reduced Part of the reason it takes 6" space to dissipate the heat around the pipe less than that changes to what it was tested and listed to

You may talk to the fire dept to read the code requirements, but they are not authorized to accept any less than what has been written in code or manufacturer's specs
 
Is space is important to you, there are stoves out there that can sit as close as 3" from a combustible wall and require no R value for the hearth.
 
Elk has it right on
with Reduced NFPA clearance you can NOT go any closer that 12" to Combustible.
That 12" is to the Drywall or wood framing that is behind your rock work.

Most stoves have clearance closer that 12" if you use double wall pipe.
so if your stove shows 7" to combustible with the use of double wall pipe then you would need to put the stove at
7" from what ever combustible (including drywall) you have behind any rock work.

some stoves are deep and load front to back (north south) and some like the Avalon Rainer (47" hearth) or Hearthstones (42" hearth) load sideways (east west) this will allow for less of a hearth.
the Heritage is a Mid size stove and with a heatshield the back of the stove is only 7" to combustible. so the Min hearth size is only 42" from the COMBUSTIBLE wall


Another way to MAKE the hearth look LESS intrusives is to TILE or thin rock Flush to you flooring hight
so it will not stick up and be a toe stubber.
 
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