How can I make THIS non-combustible??

[msm10301]

Hello, I've been lurking on this forum for quite a while, and have learned a lot, what a great site. I would like some advise on a problem I have. I have a cabin that I recently purchased, it came with a manufactured fireplace that drafted poorly and threw no heat whatsoever. I thought, no big deal, I can tear it out and install an insert or freestanding stove in its place. The chimney has cultured stone on it, so I assumed that it was constructed with cinder block, with the stone adhered to that. Unfortunately, what I found was a 2x4 framed chase with OSB sheathing. The mesh, scratch coat and stone was then attached to that. To make my day even better the chimney crown has been leaking, so now a fair amount of the bottom is rotten. How do I create non-combustible surfaces within the hole in the wall I now have, so that I can install a stove? At this point I am leaning toward a freestanding stove so that the pipe is the only thing going into the cavity. In one of the pictures you can see that there is a 12" pipe (single wall) that runs the length of the chimney and is anchored in the chimney crown cement. Can I run a pipe inside that? The original manufactured fireplace also has a 8" SS single wall pipe that ran inside of the 12", any way to utilize that? I've attached pictures to help. Thanks

 

[98dingo]

You could use some Durarock in there as a non combustible. Or if all clearance are met for whatever you decide to use for your chimney, you could just close that entire opening off and stone over the existing opening and just make a hole for the thimble.

 

[msm10301]

Thanks 98dingo, would lining the entire cavity with Durarock = a non-combustible surface and make it safe? We thought about walling the opening off as you suggested, my only reservation would be getting access to the pipe for cleaning, any thoughts?? Thanks

 

[begreen]

If you wall it all off, and the stove is inside that area, that will be an alcove installation. Many stoves have strict clearance rules for this and the height seems like it would be in violation for several stoves unless the stove was outside of the alcove. If you move the stove out of the alcove it will need a hearth built to spec for the stove too, but that will give you the best heating results. At that point, there may not be a need for cement board, especially if the stove is vented with double wall pipe.

As for the existing pipe, tear it out and put in a proper class A flue, honoring it's 2" clearances. Do a new, proper, sealed top flashing for chase and have peace of mind. Note, there should be a firestop in the chase at the ceiling height, just as if it were inside the house envelope.

 

[98dingo]

If you wall it all off, and the stove is inside that area, that will be an alcove installation. Many stoves have strict clearance rules for this and the height seems like it would be in violation for several stoves unless the stove was outside of the alcove. If you move the stove out of the alcove it will need a hearth built to spec for the stove too, but that will give you the best heating results. At that point, there may not be a need for cement board, especially if the stove is vented with double wall pipe.

As for the existing pipe, tear it out and put in a proper class A flue, honoring it's 2" clearances. Do a new, proper, sealed top flashing for chase and have peace of mind. Note, there should be a firestop in the chase at the ceiling height, just as if it were inside the house envelope.

I have to agree with you. Redoing it the correct way is the only way you can be sure everything is right. If you run new class A you could get a support for the bottom and a plug for the base. Cleaning it would involve running your brush down, taking of the stove pipe then us a brush and a vac to collect everything that is no down by the thimble.

 

[soupy1957]

I'd want to line that entire fireplace area with real brick-n-mortar, and put a free-standing stove outside the front of it, but I don't know how realistic that is, (using the brick) per any "Codes."

Can't comment on the chimney.

-Soupy1957

 

[Rob From Wisconsin]

You may want to consider installing a Zero-Clearance Fireplace unit.
Many of them can be placed right against combustibles.
Some mfr's are RSF, BIS Security & Napoleon.

Hope this helps some....

 

[98dingo]

You may want to consider installing a Zero-Clearance Fireplace unit.
Many of them can be placed right against combustibles.
Some mfr's are RSF, BIS Security & Napoleon.

Hope this helps some....

This would also be a good option. You can set a manufactured zero clearance FP inside the cavity and it can "touch" anyting but they say to leave a 1/4" of space for expansion.

 

[msm10301]

When I think of zero clearance fireplaces, I think of the clunker that I just pulled out, as you can see in the picture. It drafted poorly and threw no heat. I burned that fireplace one time, that's how enjoyable it was. Is it safe to assume that ZC fireplaces have come a long way? This one was about 20 years old.

 

[johnstra]

Xtrordinair makes a really nice zero-clearance FP that supplies good heat. They are kinda pricey, but good. They have blowers, a cat, and they can be configured for outside air.

 

[98dingo]

When I think of zero clearance fireplaces, I think of the clunker that I just pulled out, as you can see in the picture. It drafted poorly and threw no heat. I burned that fireplace one time, that's how enjoyable it was. Is it safe to assume that ZC fireplaces have come a long way? This one was about 20 years old.

Those prefab boxes were not good for much more than watching a fire most of the time. A new high efficiency FP look and heat alot better

 

[southland]

Buck has three zero clearance wood stoves, but I don't know if any will fit your situation.

http://www.buckstove.com/wood.html