Grandpa Bear III Barn Installation Questions

[Mingocreek]

Hello everyone - newbie alert. I have a Grandpa Bear III with an 8" rear vent that I plan to install in my barn. I have attached a pic of the install area and have a few questions regarding placement and stove pipe.
1) How far should I set the stove/stove pipe from the inside wall (will use brick or cement board on wall behind stove and pipe)?
2) What type stove pipe should I use in the different areas?
3) Should I reduce the pipe to 6" from the stove?
4) I will have to offset the pipe for the upstairs roof overhang. Is this OK and should it be inside or outside (as shown)?
5) Do I need to go 2" above the top ridge (about 8' away)?
Thanks in advance for your guidance....more questions surely to come.

 

[coaly]

Welcome to the Forum, I gave you your own thread since this can become involved.

First, clearance with no protection is 36 inches to the stove, 18 inches to single wall pipe. That is connector pipe that goes from stove to chimney.

If you apply solid brick directly to a combustible material, clearance can be reduced by 33% down to 24 inches.
If you build an approved heat shield, (this uses air for cooling) clearance can be reduced by 66% down to a minimum of 12 inches.

So we're on the same page, outside is Class A All Fuel Chimney, or masonry. Prefab metal can be double wall, called "pack" type or triple wall, which has thinner insulation around the inner pipe, with a third exterior outer pipe. All metal prefab have stainless inner flue.

The pipe that connects stove to chimney is called connector pipe. It must be 24 ga. minimum, black, made for stove installation. Male end faces down, and gets 3 screws at each joint. This is the single wall pipe that requires 18 inches to combustible material.

There is double wall connector pipe called close clearance pipe for down to 6 inch clearance.
Depending on the height from stove to chimney support box, over 8 feet you should use double wall pipe to prevent too much cooling from excessive height. Stoves are built for 8 foot ceiling, so as the flue gasses cool as they rise, they can form creosote rapidly. The main object is keeping the inner flue temp ABOVE 250* to the top, when smoke is present. This is the reason for double wall pipe in a high ceiling installation, and insulated pipe outside to prevent cooling as flue gasses rise.

Reduction of diameter is not allowed by code. Depending on the square feet heated, you would not want to reduce chimney size. This reduces heating capacity of stove.

Offset as needed, but straight runs are best for draft, cost, and cleaning.

The chimney rule is 2 feet above anything within 10 feet measured horizontal from chimney top. Also where it penetrates roof, it needs to be 3 feet above the roof penetration. (So if you measure horizontal 8 feet to peak, it must be 2 feet over where a level horizontal line hits roof or peak)

 

[coaly]

This is a good primer to get started; wood-stove-wall-clearances-primer

 

[Mingocreek]

Welcome to the Forum, I gave you your own thread since this can become involved.

First, clearance with no protection is 36 inches to the stove, 18 inches to single wall pipe. That is connector pipe that goes from stove to chimney.

If you apply solid brick directly to a combustible material, clearance can be reduced by 33% down to 24 inches.
If you build an approved heat shield, (this uses air for cooling) clearance can be reduced by 66% down to a minimum of 12 inches.

So we're on the same page, outside is Class A All Fuel Chimney, or masonry. Prefab metal can be double wall, called "pack" type or triple wall, which has thinner insulation around the inner pipe, with a third exterior outer pipe. All metal prefab have stainless inner flue.

The pipe that connects stove to chimney is called connector pipe. It must be 24 ga. minimum, black, made for stove installation. Male end faces down, and gets 3 screws at each joint. This is the single wall pipe that requires 18 inches to combustible material.

There is double wall connector pipe called close clearance pipe for down to 6 inch clearance.
Depending on the height from stove to chimney support box, over 8 feet you should use double wall pipe to prevent too much cooling from excessive height. Stoves are built for 8 foot ceiling, so as the flue gasses cool as they rise, they can form creosote rapidly. The main object is keeping the inner flue temp ABOVE 250* to the top, when smoke is present. This is the reason for double wall pipe in a high ceiling installation, and insulated pipe outside to prevent cooling as flue gasses rise.

Reduction of diameter is not allowed by code. Depending on the square feet heated, you would not want to reduce chimney size. This reduces heating capacity of stove.

Offset as needed, but straight runs are best for draft, cost, and cleaning.

The chimney rule is 2 feet above anything within 10 feet measured horizontal from chimney top. Also where it penetrates roof, it needs to be 3 feet above the roof penetration. (So if you measure horizontal 8 feet to peak, it must be 2 feet over where a level horizontal line hits roof or peak)

Thank you so much Coaly for responding. That is exactly what I needed to get started. I have been looking around on these forums and they contain so much useful information it can sometimes get a little overwhelming for someone trying to figure it all out. I bought the woodstove years ago and used it when we were building the barn. We used very basic piping and the stove didn't seem to put out much heat. From reading through the Fisher stove treads though I obviously was doing something wrong and am looking forward to getting it set up correctly.

I found early on to look for your threads ....I purchased the Woodburner's Encyclopedia that you recommend and it too has a lot of information. Once I get the stove cleaned and painted, I may post a pic to make sure it is what I think. I'm using your recommendations from earlier posts on the restoration and also on a baffle.
Again, thanks.