Protected Wall Question

[hydestone]

Hi there:

I am remodeling my kitchen area to include a wood stove and am trying to minimize how far the stove sticks into the room, since the kitchen is not huge.

1. The wall behind the stove is the wall that encloses the chimney. Currently there is only wood framing in place.
2. I want the back wall to be brick veneer.

I am having a difficult time coming up with a protected wall that is thin and doesn't have exposed sheet metal. Also, I am having a tough time figuring out how to incorporate the 1" of ventillation space at the top and bottom of the wall, and my wife doesn't want to see it at the top.

My initial thought was to install Micore board over the wood framing then install the masonry veneer on top, but that doesn't seem to fit any of the protected wall configurations in NFPA 211. They all seem to require a ventilation space.

There is one option that doesn't require ventilation, which results in some reduction, but only gets 9" instead of 6" in back. Would installing Roxul fire safing batts between the studs and Micore over the top work for that? Or does the mineral fiber need to be on top of the framing?

I've attached a picture with the installation we are trying to achieve.

Any suggestions are appreciated, including attractive ventilation solutions at top and bottom.

Thanks,
John

 

[webby3650]

The 1" air space is what is doing the work here. There's no way around it if you want a properly protected wall. Does your stove manufacturer give you details in the manual about reducing clearances? Many don't allow any further reduction than the numbers given in the manual.

 

[hydestone]

I've got a Jotul 602 and F3CB, currently planning to use the F3CB, but am trying to make accommodations for upgrading to am F500 if the F3CB doesn't do it...or if I get tired of cutting wood up into tiny pieces to fit in the stove.

I suppose the 1" gap could be created with some sort of black metal frame, instead of staggering bricks to get the opening.

 

[hydestone]

I am going to use 1" spacers, 24 gauge sheet metal, 1/2" durarock, and 1/2" brick veneer for the wall construction.

At the bottom, instead of using bricks below for support, as shown in NFPA 211, I'll use short 6" pieces of angle iron screwed back to the studs to support the wall assembly, staggered like they show the brick. It will look like an open slot along the back wall.

At the top, I'll leave a 1" opening from the ceiling. I'll stick brick veneer to the top, but keep it off the wall 1", so I don't close up the ventilation slot.

Thoughts on this construction?

 

[webby3650]

Does the F3 allow additional clearance reduction if the wall is protected?

 

[hydestone]

Yes it does. 6" from sides, rear, and corner with rear heat shield, double wall chimney, and protected construction.

 

[begreen]

I am going to use 1" spacers, 24 gauge sheet metal, 1/2" durarock, and 1/2" brick veneer for the wall construction.

At the bottom, instead of using bricks below for support, as shown in NFPA 211, I'll use short 6" pieces of angle iron screwed back to the studs to support the wall assembly, staggered like they show the brick. It will look like an open slot along the back wall.

At the top, I'll leave a 1" opening from the ceiling. I'll stick brick veneer to the top, but keep it off the wall 1", so I don't close up the ventilation slot.

Thoughts on this construction?

Sheet metal is superperfluous, not needed. If the brick stops an inch from the ceiling it would vent better. This gap at the top would be barely noticeable from eye level.

 

[ddahlgren]

Maybe an expanded metal grill top and bottom painted so color that blends in? If yes be sure to double the gap to 2" to make up for the space the metal takes up.

 

[Highbeam]

Yes it does. 6" from sides, rear, and corner with rear heat shield, double wall chimney, and protected construction.

That's good news. All too often people assume that they need to build an air gap non-combustible wall behind a stove. Turns out, if the back wall is beyond the required clearances to combustibles then you can make it out of bare plywood, any additional protection is just for bonus safety which isn't a bad thing but it isn't required. Very few stoves allow a reduction in their published clearances to combustibles for a NFPA wall shield.

I have painted sheetrock behind my stove. 6" away from the stove!

 

[ddahlgren]

Just keep in mind the heat shield is seldom needed for daily operation it is for when the SHTF moments so you may not know if right until you really need it.

 

[begreen]

During normal operation proper clearances or shielding will also keep the risk of pyrolysis from happening over a long period of time.