Half-height alcove ok for unlisted stove?

[JulieC]

I am in the planning process for a small (12'x18') rustic (off-grid) weekend cabin in southern Ohio. The goal is a CHEAP place for us to stay until we build a real house on the 21 acres my husband inherited. There is no entity with the authority to enforce the residential code (I asked a building code question of the state and was informed as such) and it's only slightly larger than the "don't need a permit" line (200sf) anyway) for this county.

A small, old wood stove has been offered to us. It is approximately 1' wide and 2' deep. Older than dirt, thus, "unlisted". I've been looking around at clearance specs until my head hurt. I get how to reduce the clearances on two (full wall sides, say back and right). What I would like to do is built a half-height wall on the left to keep my clumsy self and clumsy child from tripping into it from the side. I keep seeing "alcove warnings". Is this a reasonable thing to do, if the half-height wall is protected in the same way (vented airspace with masonry wall covering, wall height in this case) the full height walls are?

I drew a quick pic with Paint. The thick blue lines are exterior walls, the red is the proposed half-height wall, the green is the vented masonry wall, the grey box is the stove. Is this ok or not? Suggestions?

 

[fossil]

The green lines in her drawing are ventilated wall heat shields with 1" airspace, Pook. I'm trying to think of any problem with this plan and I haven't come up with anything yet. Always gotta keep in mind the required clearance from the wall of your stovepipe, as well, of course. Rick

 

[fossil]

The whole idea of a heat shield is to be able to reduce clearances to combustibles. The heat shield is completely non-combustible, and the surface temperature might well get very high. It then conducts that heat through its thickness, where the convection established in the airspace carries it away, up and out, thus protecting the combustible material on the other side of the shield. The masonry shield behind my shop stove can get quite uncomfortably hot...but the combustible wall behind that on the other side of the airspace won't. I can feel the heat rising from the airspace along the top of my shield. Rick

 

[fossil]

Infrared thermometer? I don't even have a cell phone that takes pictures. %-P Rick

 

[dougand3]

The half wall with all it's masonry work in such a tiny space? Bet heat would move much better with just the 2 exterior walls. And unlisted stoves are 36" clearance to combustibles - which is a standard number. There may be a standard number for a non-combustible wall - I don't know it, tho. Stove manufacturers set this non-combustible clearance number in the stove manual - and yours is too old to have one.

 

[DAKSY]

Unlisted stoves - per NFPA 211 - must have a 36" clearance to combustibles...
Approved heat shields can reduce this clearance by 33%,
so, if you don't have 24" to your combustible walls - behind
your heat shield - you're LITERALLY playing with fire...
Inspector or no inspector, I would not consider it safe.

 

[fossil]

Actually, IAW NFPA 211, Table 12.6.2.1, wall clearances can be reduced by 66% with an appropriately constructed and installed heat shield, which brings the minimum distance from the stove to the nearest combustible wall for an unlisted stove down to 12" (measured as though the shield weren't there). This space has the additional advantage that the wall on one side is only about as high as the stove is tall, and I'm assuming normal ceiling hieght (or nearly so) throughout...so it really is not a typical "alcove" installation. Rick

 

[DAKSY]

I stand corrected. 66% it is... Guess I should refrain from citing specs when they're at work & I'm at home...
Thanx for straightening me out!

 

[dougand3]

It makes alot more sense after Rick 'splains it.