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[Mr. Henry]

Hi everyone, as you can see I'm new to this site. I just really need answers to some very specific questions. I'm restoring an 1830 farm house with what I think is an original Rumford fireplace with a Beehive oven. I have rebuilt the chimney, 1' below roof line up, and inspected the interior that actually looks real good. I've even built a couple of small fires but don't dare for fear of burning the house down. I really want this thing to function but I don't want to devalue it's authenticity. Here are a few specs, the face of the fire box is 4'x3.5'. It has the classic modified breast/smoke chamber, but no damper. The interior of the stack is aprox. 14"x24". The height of the stack from hearth to crown is about 25'. the interior is like a small case y, that's upside down, the smaller leg of the y branches off to the oven. I want to line it for the obvious reasons, a 12" liner for the fire box and maybe a 3" for the oven. I've read ratios in regards to liners vs. the opening of the fire box being 8:1, and i'd like the liner to be easily converted from an open fireplace to a wood stove. I fear the 12" liner is too small, there would be no way to dampen the draw, a liner devalues the authenticity, the 3" liner may be too small as well, ( you just shovel embers into the oven for cooking)... I am thinking about lining the smoke chamber with a ceramic blanket, holding it in place with metal lath and re bar to insure proper placement of the liner and then finishing it with high temp cement. This fireplace is 1 of 5 or 6 major architectural details that make this farm house unique. Any replies are appreciated, I'm sure, some one must know the proper procedures to insure safe operation, that wont compromise the historical integrity of such a fireplace, Thanks.

 

[Jags]

At this point, I don't really have anything to add other than PICS PLEASE.

 

[edthedawg]

The interior of the stack is 14x24 - big enough to stand up inside of it then?? That's massive - i'm trying to imagine any "draw" in a column with that kind of cross-section... OK enough speculating... in lieu of photos, it sounds like you want a lot of flexibility for your house, while not permanently altering or destroying any original character, but also allowing you to hook up anything you want in the future, including possibly just burning a plain open fireplace if you choose.

That about sum it up?

It seems like you could put a variety of liners with a big custom block-off plate at the top of bottom of the flue, and pack it all w/ insulation (or use insulated liners).

I'll attach a quick sketch showing 6" (stove), 12" (wide open fireplace), and 3" (gas - or is the oven not gas?) cylinders inside of a 14" x 24" rectangle. Seems like your lath/rebar/blanket/cement idea would be messy, fragile, and potentially would do more to disturb your house's character than a simple set of liners, thereby allowing you to selectively install / blockoff flues as desired, without causing code issues.

 

[meathead]

does the beehive oven currently have a flue exiting it? Are you sure the design calls for embers to be shoveled into the oven for baking purposes? Any chance the beehive oven utilizes radiant heat from the fireplace to obtain the temp to bake bread etc?

 

[Mr. Henry]

I took a couple pictures of this fireplace, I hope it helps...

As you can see, someone closed the door to the oven before the embers were done burning, so I just painted it. Right above the 60 degree jog in the stack, is a wood lined cabinet, I read somewhere that these old timbers can ignite at around 250 degrees f. The entire thing was blackened by coal soot or an oil fired furnace, the mantel is hand carved from what I suspect may be beech, but I wouldn't strip it. The idea of a plate is interesting but how could I keep heat from entering the stack around the edges?

 

[edthedawg]

I can't see your pix from work (firewall) but assuming I understand your question, you would just bend the edges of the plate down to give yourself a screwing "flange" all around, then some combination of a ~3" rockwool insulation blanket on top of the plate and/or some high-temp cement around the irregular firebox perimeter would effectively "seal" that joint.