Wood Stove Alcove

[paulestuart]

Hey All,
Just found this site, awesome. I'm trying to build a wood stove alcove, almost complete actually and had a few questions (EG I may have made a mistake). Mfr calls for a 36" wide alcove with 25" depth. Got that, I used hardibacker for the fire resistant material - does anyone see a problem with this. I'm a little confused by its R value. The hardibacker is backed with wood studs. Also, trying to blend cement board with drywall - outside corner - an I'm wondering what works best for this. I'm leaning towards a metal corner with durabond - but open to suggestions. Sorry no pics camera is "lost" in boxes while trying to move while renovating.

Thanks,
Paul

 

[CarbonNeutral]

Does the hardibacker sit further than the required distance to combustibles?

You can't do distance to studs as hardibacker is not considered non-combustible (it has a combustible filler). Because of this, the r-value of Hardibacker is not relevant.

If you're far enough away from the stove, then it's not an issue, but at 36" wide for the alcove, plus the clearances, that's one mighty small stove - I hope I'm wrong but I think you could be in trouble. Even if the hardibacker was replaced you still have the wood studs - there is no material that you can put in front of these that would reduce the clearance distance.

EDIT: unless we are talking about the hearth pad, then there are specified r-values, things you can do, but the walls - that's a different story

 

[Wood Heat Stoves]

is this going to be inspected by the county? consult a pro if you dont understand the stove manuals manual recomendations or general stove codes enough to figure the construction out.
have seen many alcoves specially built improperly.

are you trying to reduce stove clearances using nfpa211 guidelines? what stove is going in? when was it made, and does the manual say if you can reduce alcove clearances using nfpa211?

if you can leave air spaces behind the backer, open to air flow, all the better

 

[begreen]

Hi Paul, what is the stove make and model? Generally it's good to exceed minimum specs if possible. You'll want to use pure cement board like the original Durock or Wonderboard, but not their next gen product which has styrofoam beads added to make it lighter weight.

 

[paulestuart]

Hey everyone,

Thanks for the help. The stove I got is a jotul F3 for secondary heat and ambience. The minimum manufacturer specs for alcove width is 36" and depth is 25", so i built it to min. specs. Min. specs call for double wall pipe, I was hoping to run around this by using cement board on the walls, sounds like this is a no go from previous posts.

I'm now wondering if I could double up durock up the walls to 40" (with tile) from the floor and then run fire retardent drywall up to the ceiling? Or maybe tile up to the ceiling. What do you all think.

Perhaps, I should just go with the double will pipe, just a little worried about aesthetics with this system. Is their a way to make double wall look OK?

Thanks Again,
Paul

 

[CarbonNeutral]

Hey everyone,

Thanks for the help. The stove I got is a jotul F3 for secondary heat and ambience. The minimum manufacturer specs for alcove width is 36" and depth is 25", so i built it to min. specs. Min. specs call for double wall pipe, I was hoping to run around this by using cement board on the walls, sounds like this is a no go from previous posts.

I'm now wondering if I could double up durock up the walls to 40" (with tile) from the floor and then run fire retardent drywall up to the ceiling? Or maybe tile up to the ceiling. What do you all think.

Perhaps, I should just go with the double will pipe, just a little worried about aesthetics with this system. Is their a way to make double wall look OK?

Thanks Again,
Paul

These are the minimum for a 'protected' alcove installation. My understanding of protected is a secondary, non-combustible wall spaced out a certain distance from combustibles with non-combustible spacers - the air gap provides the required heat shield from the radiant heat. The secondary wall is lifted from the ground to allow air flow through the space.

If you do not have a protected wall, the minimum alcove for the F3 is 71" by 40". That's pretty much it - I don't see any safe way of fudging this. You need that air gap and air flow.

 

[edthedawg]

Paul,

Good to see you posted this over here. These guys'll steer you right!

Sounds like you are doing this all on the sly? No insurance co or building inspector contact involved?

 

[paulestuart]

Thanks again for the posts,
Sounds like I will need to go with the double wall system. Does anyone have a picture of something like this?
Thanks

 

[CarbonNeutral]

Your F3 manual has some rough schematics, but not the details you would need to make it safe.

 

[paulestuart]

Carbon,
where can i find the details to make it safe?
thanks

 

[CarbonNeutral]

NFPA codes I would guess and depending how clear they are, experience. I, like you, want to get things done myself, but this may be time to turn to a pro (that itself will be a challenge)

 

[paulestuart]

last post - found a hearth dealer here in Bellingham who sounds eager to help me out. Thanks for everyone's advice, you probably saved me from burning down the hood. I'll update with some pics when i find camera and job is done. Stove not in stock til November, so it may be awhile. Then I'll need help on how to properly burn the wood.
Thanks Again,
Paul

 

[CarbonNeutral]

Good luck to you - sometimes people come on here looking to validate something that they know, deep down, is wrong, and they won't hear anything else - you and your family will now be much safer because that wasn't you. Looking forward to the pics....

 

[Dave_1]

paulestuart,

Good visuals & specs

(broken link removed to http://woodstocksoapstone.net/pages/hearthplan.html)