New Alcove Stove Installation in old Chase

[p301]

Ok so this is the first forum i've ever joined for anything and would greatly appreciate any advice i could get. I have been using wood burning stoves for a long time at a camp i have in the Adirondacks but am looking to make the move into installing one in my home. I am looking to tear out my existing zero clearance fire place and turn the existing chase into an alcove. I know protected surfaces would be in order and have been looking at either the Lopi endeavor or the hearthstone Shelburne I'm open to other recommendations as well that would give me longer burn times but not blast me out of the room with heat. I guess to start i have a few main questions. And incase it is helpful the outside dimensions of my chase are 67" wide x 32 " Long including the vinyl siding so take a little off for that.

1. Traditionally are zero clearance fireplaces built with the floor joists cantilevered off the house or is the whole chase and fireplace kind of like an afterthought and its just attached to the outside of the house. I worry about the weight of the stove and the stone and the protected surfaces and Durorock either way but much more so if its the latter. I will of course cut open my garage ceiling and double check before i start but just curious as to what others have seen, is weight an issue in these installations?

2. The Shelburne wood stove alcove calls for protected surfaces but does not say what method to use. I would assume they want one of the 66% reduction methods of which there are several. The Lopi endeavor specifically calls for using 3 1/2" masonry surface with the 1" air gap in their detail does that mean i cannot use any other type of 66% reduction protected surface I had wanted to use Durorock with cultured stone but if the stone is 2" and the Durorock is 1/2" that leaves me an inch short. Does one put 3 layers of 1/2" Durorock and make the whole installation even heavier or can i use any 66% reduction method?

3. If you are creating side and ceiling protected surfaces does the side and back top openings for convection need to be installed or can it be connected straight through to the 1" air gap and into the ceiling protected surface and then have all the openings facing the room with an equal amount of opening space as the sum of all of the bottom.

4. Any recommendations on running the chimney outside the existing chase vs through it. A Tee on the outside of the chase sure would make cleaning it a lot easier but it sure would look a lot nicer inside of the chase. I have a high steep roof that i really have no desire to go on to clean this thing from

Thanks for the help and i'm sure i will have many more questions as this progress, but i want to do it right the first time so i am not worrying about it

 

[Rickb]

As far as stoves go, if you are looking for long burns and something that wont heat you out of the room look for a good Cat stove, like the blaze king stoves.

As far as stone goes you can not use 3.5" stone with out the base being on concrete. Its just way too much weight. That said depending on the stoves some have very low back and side distances. And some can be further reduced with shielding. Also watch for if the stove is ember protection only underneath. Some stoves have very high R value requirements underneath.

 

[Rickb]

As far as stoves go, if you are looking for long burns and something that wont heat you out of the room look for a good Cat stove, like the blaze king stoves.

As far as stone goes you can not use 3.5" stone with out the base being on concrete. Its just way too much weight. That said depending on the stoves some have very low back and side distances. And some can be further reduced with shielding. Also watch for if the stove is ember protection only underneath. Some stoves have very high R value requirements underneath.

as far as chimney..... Go straight up the chase. Better drafting, and you can buy a soot eater cleaning system and clean it from the stove up. Very little to no mess and no need to get on the roof.

 

[DanCorcoran]

The following is from the Shelburne manual. For my installation, I bought an Imperial Stove Board at Ace Hardware. It consisted of a sheet of micore with a thin metal cover and has an R value of 1.1. Because it didn't look very attractive, I glued tile to the top...see photo.


Install your stove on one of the following:

A floor protector with an R-value of 0.8 or more that you obtain from your dealer. A floor protector is any noncombustible surface laid on the floor underneath the stove that extends, 16 inches -US (46 cm -CA) beyond the front door and 8 inches (203 mm) beyond each side of the fuel loading and ash removal opening(s).
For horizontal chimney connector installations, the floor protection must be installed beneath the connector and 2” beyond each side. To determine the R-value of the proposed alternate floor protector, do one of the following:

If the R-value is given, use that value—no conversion is needed.

If a K-factor is given with a required thickness (T) in inches, use this formula: R-value = 1/K x T

If a C-factor is given, use the formula: R-value = 1/C
To determine the R-value of the proposed alternate floor protector:

Use either the K-factor or the C-factor formula explained above to convert specifications not expressed as R-values.

For multiple layers of floor protectors, simply add the R-values of each layer to determine the overall R-value of the layers.
If the overall R-value of your setup is greater than the R-value of the specified floor protector, then your setup is acceptable.

 

[p301]

thanks for all the suggestions guys I think i'm pretty set with the hearth i have plenty of room to meet the required R value. My biggest concern is the protected wall surfaces and celiing with the weight and why is the lopi manual calling specifically for a 3.5" masonry wall for a protected surface and not just any of the 66% nfpa reduction methods while the hearthstone manual just says protected surface. what else has anyone done in an alcove to combat the weight issue. As far as the blaze king i think ill have at most a 48" clearance inside the alcove when i'm done i'm at work and looked quickly but it didn't look like it would fit. Is there much maintenance with the cataylist i'm kinda old fashioned and wish i could just actually still buy a good airtight stove. How much weight can be put in say a 30" cantilever of a house? I could weld up some 45 degree brackets and tie the cant back to the foundation wall with that but i dont want to get involved with that unless absolutely necessary

 

[begreen]

Ok so this is the first forum i've ever joined for anything and would greatly appreciate any advice i could get. I have been using wood burning stoves for a long time at a camp i have in the Adirondacks but am looking to make the move into installing one in my home. I am looking to tear out my existing zero clearance fire place and turn the existing chase into an alcove. I know protected surfaces would be in order and have been looking at either the Lopi endeavor or the hearthstone Shelburne I'm open to other recommendations as well that would give me longer burn times but not blast me out of the room with heat. I guess to start i have a few main questions. And incase it is helpful the outside dimensions of my chase are 67" wide x 32 " Long including the vinyl siding so take a little off for that.

1. Traditionally are zero clearance fireplaces built with the floor joists cantilevered off the house or is the whole chase and fireplace kind of like an afterthought and its just attached to the outside of the house. I worry about the weight of the stove and the stone and the protected surfaces and Durorock either way but much more so if its the latter. I will of course cut open my garage ceiling and double check before i start but just curious as to what others have seen, is weight an issue in these installations?

2. The Shelburne wood stove alcove calls for protected surfaces but does not say what method to use. I would assume they want one of the 66% reduction methods of which there are several. The Lopi endeavor specifically calls for using 3 1/2" masonry surface with the 1" air gap in their detail does that mean i cannot use any other type of 66% reduction protected surface I had wanted to use Durorock with cultured stone but if the stone is 2" and the Durorock is 1/2" that leaves me an inch short. Does one put 3 layers of 1/2" Durorock and make the whole installation even heavier or can i use any 66% reduction method?

3. If you are creating side and ceiling protected surfaces does the side and back top openings for convection need to be installed or can it be connected straight through to the 1" air gap and into the ceiling protected surface and then have all the openings facing the room with an equal amount of opening space as the sum of all of the bottom.

4. Any recommendations on running the chimney outside the existing chase vs through it. A Tee on the outside of the chase sure would make cleaning it a lot easier but it sure would look a lot nicer inside of the chase. I have a high steep roof that i really have no desire to go on to clean this thing from

Thanks for the help and i'm sure i will have many more questions as this progress, but i want to do it right the first time so i am not worrying about it

1. Good to think about the weight. Chase construction varies. Some ZC have the chase on a slab extension, others on cantilevered joists, some on their own foundation extension. You'll need to have your specific situation evaluated for the weight it will be carrying. Most likely it will not be an issue, but worth checking.

2. An NFPA 211 protected surface can be protect by several means. The main thing is that it needs to be open at the top and bottom to allow air to freely convect behind it. You could use 24ga sheetmetal, cement board with tile or stone veneer or brick as long as the 1" air space is established behind it and it is open top and bottom by at least an inch.

3. https://www.hearth.com/talk/threads/wood-stove-wall-clearances-primer.147785/

4. Run it up the chase and get a stove that has an easily removable baffle so that the flue can be cleaned from the bottom up through the stove. A Gardus Sooteater is a popular tool used to do this.

There are many alcove installation threads here. Search in this forum for "alcove" to locate examples.

 

[p301]

begreen thats what i thought about the protected surface too but if you look at the file i am attaching the lopi stove calls specifically for 3 1/2
thick masonry witha 1" air gap. I am in agreement with you that i think any of the protected surfaces that meet the standard should all be considered equal however none of those are mentioned or listed in this manual. I would assume i can not give this to the inspector and put up a piece of sheet metal and tell him its the same thing. Maybe i will put a call into lopi and see if they can send me something stating i can use other methods of constructing a protected surface.

As far as my existing chase goes it is cantilevered and hangs over a boulder wall so there is not any good way to reconstruct it with a more solid footing which is why i am concerned about the weight issue

 

[begreen]

Yes, I've read the Lopi docs. It's one method, but not the only approved method. Here is a chart showing options:
https://www.hearth.com/talk/wiki/nfpa-wall-clearance-reductions/

For a proper ventilated wall shield NFPA 211 12.6.2.1 c-h are also options. There are many inspector approved ventilated wall shields with just metal, or tile over cement board. When in doubt, ask your local inspecting authority and quote the actual line of NFPA 211 that you are inquiring about.

 

[p301]

ok great that solves a big issue there i thought once the manual listed it specifically that was the only way it was tested and that was the golden rule.
Now i am just stuck with the weight issue and what that thing can support inside the 30" overhang i'd like to go with some stone on durarock but im starting to think sheet metal or tile may be the smarter move

 

[p301]

Ok so after much deliberation i think i've settled on the hearthstone shelburne for a wood stove. I'm planning out my alcove and am running into some questions about the protected surfaces that will need to be located most likely on all three walls and the ceiling and how they will interface with each other. If anyone has any experience and could help me out on this one id greatly appreciate it. I know the bottom of all the vertical walls are to have a 1" air space with a 1" opening top and bottom (the sides will be closed) should the interior corners be closed off from each other so each wall is its own ventilated air space, or should they all be connected so there is one large U shaped ventilated air space that is all connected either one is easy enough to do

Secondly i'm trying to wrap my head around how the ventilated air space on the ceiling will work. The ceiling will be flat but id like to add an arch in the front for aesthitics. Should the openings for the air gap be on the left and right side of the stove or front and back side of the stove or does it not matter? Or should the opening for the air gap be on the back side of the ceiling facing down and then show somehow on the vertical surface of the arch (Id rather not do it this way) Do i need to worry about heat being trapped behind the arch which will maybe hang down slightly below the ceiling and cause the temps to rise to a dangerous level at the ceiling?

Again any help is greatly appreciated im not concerned about the work just about making sure everything is done safely and correctly

 

[husky345 vermont resolute]

The following is from the Shelburne manual. For my installation, I bought an Imperial Stove Board at Ace Hardware. It consisted of a sheet of micore with a thin metal cover and has an R value of 1.1. Because it didn't look very attractive, I glued tile to the top...see photo.
View attachment 189254

Install your stove on one of the following:

A floor protector with an R-value of 0.8 or more that you obtain from your dealer. A floor protector is any noncombustible surface laid on the floor underneath the stove that extends, 16 inches -US (46 cm -CA) beyond the front door and 8 inches (203 mm) beyond each side of the fuel loading and ash removal opening(s).
For horizontal chimney connector installations, the floor protection must be installed beneath the connector and 2” beyond each side. To determine the R-value of the proposed alternate floor protector, do one of the following:

If the R-value is given, use that value—no conversion is needed.

If a K-factor is given with a required thickness (T) in inches, use this formula: R-value = 1/K x T

If a C-factor is given, use the formula: R-value = 1/C
To determine the R-value of the proposed alternate floor protector:

Use either the K-factor or the C-factor formula explained above to convert specifications not expressed as R-values.

For multiple layers of floor protectors, simply add the R-values of each layer to determine the overall R-value of the layers.
If the overall R-value of your setup is greater than the R-value of the specified floor protector, then your setup is acceptable.

Looks like the cat is content with the stove. Looks great [emoji1303]


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