Stove clearance confusion

[jparker]

I am new to standing wood stoves and trying to educate myself prior to purchasing a new stove to go on an existing hearth. The existing hearth is brick and goes up the wall about four feet and is 4.5 inches thick with no built in air gap. I am trying to determine what the clearance needs to be between the back of the stove and the brick.

Does the rear clearance listed in wood stove manuals cover the distance between the stove and the brick or the distance between the stove and the combustable framing behind the brick? For example, if the manual calls for 8" of rear clearance, does that refer to 8" off the brick or 8" off the combustable framing behind the brick?

To add to that, I see some manuals that state the rear hearth protection is one number and the rear clearance number is another. For example, in the F3CB manual, it states the rear hearth protection is 8" but the rear clearance for double wall is 6" from protected surfaces. I am having a difficult time seeing the difference between these two.

I appreciate any feedback.

 

[begreen]

The clearance is measured to the nearest combustible. In this case that could be the studs in the wall behind the brick unless the bricks were applied to drywall.

The 6" rear clearance for the F3CB is only when there is a proper, NFPA 211 shielded wall behind the stove. In that case, the hearth would go to the wall. If the stove was further out into the room then the hearth could stop 8" from the rear of the stove.

Note that the F3CB needs a hearth with an insulation value of R=1.1. Standard 4" brick is not quite enough to meet that criteria. It has an R value of .8.

 

[jparker]

I guess my confusion was around the distance to nearest combustible. I was originally thinking that the distance to the rear wall (brick in my case) could be less than 6" (using the FC3B as an example) as long as the distance to the combustible material behind it was more than 6" from the rear of the stove.

I have been trying to find a way to make this existing brick hearth work by it might just be easier to rip it out and replace it with something larger so that my choice of stoves increases.

 

[begreen]

There are many stove choices. I wouldn't get fixated on one or two brands.

 

[jparker]

I 'm not trying to stick to any single brand, just using the Jotul as an example. The issue I am currently dealing with is a small hearth and trying to stick with a straight stovepipe. It seems like most stoves I look at don't work in my setup because of clearances.

I was just looking at the BK Ashford 20.2 and it looks like it would work. Center pipe on the Ashford is 15.875" and my stove pipe center is 16" from the wall. The rear clearance is 6 1/2" and I would have 6 7/8" to combustibles but there would only be 2 3/8" between the back of the stove and the brick hearth. I don't know if that presents an issue.

I was also looking at the PE T4 as it looked like it would fit but the only local dealer doesn't believe that she can get one (low stock because of EPA 2020 or so I am told). I like the idea of the BK for the long burns and the ability to dial it back for a smaller room. Stove will be going in a ~400 sqft area with an 8' doorway to 8' hallway going to 800 sq ft area. There is good airflow out of the room into the hallway when using electric heat. Main use is supplemental heat. Will be used everyday but not 24/7.

I have attached a diagram of my hearth for reference.

 

[begreen]

Sounds like the Ashford would work ok. Is there a combustible mantel above the stove? Can you post a full picture of the current hearth?

 

[jparker]

The mantel is brick as well. I know that the rear clearance to combustibles would be met but I wasn't sure if there was any reason to limit the distance between the brick and stove since that is a mass that absorbs heat as opposed to open air.

I don't have a picture on me but the diagram above covers all the measurements and the entire hearth is brick in mortar.