Masonry heater chimney questions

[Tony_J]

Hi,
I wish I had found this forum sooner! We are building a Tempcast in a house with a 30 foot ceiling. The chimney consists of 8 inch clay flue tiles inside of 16
x8 inch concrete column blocks. The flue tiles are wrapped with ceramic fiber liner and the blocks are filled with concrete with #4 bar at each corner running full length. The stove itself will have a facade of 4-5 inch thick granite stone. However, in order to maintain 2 inches of clearance to a wood beam, the chimney will be covered with granite thin stone veneer that matches the stove stone quite well. We cannot decide exactly where to make the transition to metal stove pipe. I don't think I want it to go much higher than it is now. I want it to look pleasing. I am concerned about the metal pipe proximity to the balcony railing. If necessary, I could construct this railing entirely out of steel, or perhaps I could include a heat shield. I'm very interested in knowing what you think about this height. Thank you.

 

[KeithO]

Normal class A has a 2" clearance to combustibles. Since the class A will be much smaller in diameter than the masonry flue, you shouldn't have a clearance problem at all. I'm guesing it will be an 8" diameter ? You do have to use a listed connector to make the transition from the masonry to class A chimney and everything in the metal chimney has to be UL listed and "factory built".

 

[JohnnyBravo]

looks awesome. why don't you want to carry the stone chimney to the ceiling? i know that a class a chimney passing through a second story needs to be enclosed, im not sure of the specific rules in your situation. i think the heatshield may look out of place, so far everything is neat and clean. heatshields look like an afterthought, implying poor planing. i think you are at a good piont and im sure you will hear some opinions here.

 

[Tony_J]

looks awesome. why don't you want to carry the stone chimney to the ceiling?

Because of the small size of the chimney, (about 18 inches square), I didn't think it would look right to go the whole 30 feet up to the ceiling. As this is our first (and last!) house and fireplace, I made a bunch of mistakes I wish I could re-do. I would basically do everything different. Now I just need to get it finished so we can move in.

 

[KeithO]

This is the ultimate site to look for info on masonry heaters. http://mha-net.org/html/gallery.htm I don't think your heater would lok in any way odd with the change to a class A chimney. If anything, I would have kept the masonry portion of the chimney at the same height as the main heater itself to keep the look more symetrical. It would also allow a reinforcement to be placed between the main heater and the top of the masonry portion of the chimney (not sure if you intend to stack wood in the niche in between ?).

 

[Hogwildz]

I am fairly ignorant when it comes to masonry heaters. What I have read & researched is kind of contradictory to what you have.
The heaters I have seen are more designed to have channels somewhat snaking around and before going upwards. Yours seems to have a firebox with a chimney connected to the side? Isn't the purpose of a masonry heater to channel the exhaust & heat around a bit to heat the stone well before going up the chimney?
As I said, I know only what I have seen & read. Just curious as to your design.

House looks like it will be very nice btw. Already looks nicely laid out.

 

[Tony_J]

I am fairly ignorant when it comes to masonry heaters. What I have read & researched is kind of contradictory to what you have.
The heaters I have seen are more designed to have channels somewhat snaking around and before going upwards.

Well, it's a standard Tempcast 2000. The flue exits at the bottom of the fireplace so therefore it does have to circulate up and around the stove before it exits. When I originally laid it out (which was years ago, we've been building this house over 7 years now) I was trying to keep from intruding into the living room any farther than I had to. So I got the stove tucked up under the framing too far. Therefore I'm forced to use thin stone veneer to keep the chimney as small as possible. I guess it'll be OK. The biggest problem is the cost of the veneer corners. The corners are about 20 dollars per linear foot, and there are 4 corners required so while everything else is cheap (flue tile, column blocks, concrete and rebar) the corners alone are 80 dollars per foot! Pretty expensive to save a few inches of living room. Of course, you don't actually have to use corners, but then it would look fake, and since nothing else in the house is fake, I'd hate to mess it up at the end. Just a word to the wise: give youself a little extra room!