Jason Pritchard

Thanks for the reply Tony. Very helpful indeed. Looks like you're getting close to firing the stove up. I'm thinking I will need to support the cfb if I choose to use the tiles I have as they don't span the top from brick to brick. I'll have to experiment a bit. I also plan to coat the cfb, as you did, with a water glass solution and hope that it slows the absorption of moisture. Best of luck on the fire up!

Very well executed build you have there Tony. I'd be thrilled if mine turns out half as good. Couple questions if you don't mind? You mentioned earlier that the cfb got quite soggy when in contact with your mortar. Did you do anything to remedy that or did it stiffen up upon drying?

I'm guessing you used low density cfb; is that all you have supporting your granite slabs or does the metal frame have a lip that the slabs rest on? I'm hoping the cfb will support some porcelain tiles I had planned to use as the topper, but wasn't sure if I would need some bracing; which would further complicate my already complicated build. I'm thinking high density cfb may do the trick if LD is not up to the task. I'm headed down the hill to look at some today and compare prices and such.

I very much wanted to keep things simple, as you suggested, but my space restraints forced deviating from the plans. Thank you for any thoughts!

Wonderful progress Tony! I'm working on frames and doors this week and hope to lay the first course next week. I'd like to hear more about your white oven design if you care to share. Will it be a steel box that sits in the oven area just above the lower tunnels? Do you plan to weld that to the door frame as a way to keep it sealed from the stove gasses? I'm learning much from your build, so thank you for continuing to document your progress and thoughts.

Thank you for the detailed explanation Tony; it's very helpful. I'm guessing the idea with the twisted wire, and your thin strapping, is that the lesser amount of expansion/contraction will be so minute that it shouldn't cause any issues because of its size? As opposed to pieces of the angle protruding into the mortar that will certainly experience more movement. I like the strapping/wire idea.

I saw that Austin had issues with drilling into the bricks and have been pondering alternatives ever since. I'm now thinking about running wire into the mortar and then running strapping into the firebox and oven areas. Predrilling holes in the bricks and then lining up the strap, drill a hole through that, at the appropriate predrilled location on the bricks, and sinking a few screws in that manner. Thus having both the wire anchored in the mortar and the attached strapping anchored into the bricks themselves as a robust way to keep the doors in place. Thanks for the inspiration and the photos!  

Is that little "fin" in the second pic how you'll be attaching your doors/frames to the stove itself? Do you have places you plan to use masonry screws that go through the door frames and into the bricks themselves? I'm still not sure how I plan to make the connections.

My bricks surrounding the oven and firebox door openings are quite short and I'm a bit concerned on how they'll hold up through years of use. Although, I did put some Tapcons in a rather small brick and whirled it around quite aggressively, trying to force a failure, and it held without any signs of stress.

I plan on pouring my insulated slab in the next couple of days and will begin work on my doors and frames while it cures. Those doors look beefy! Thanks for the inspiration and sharing your build.

Thanks Burra. I'm glad to know your thoughts on the matter and appreciate the quick reply. Looking forward to the rest of the build!

Thank you for sharing this build Austin and Burra. It is very helpful as there are so few builds showing the process of putting together one of Matt's stoves. I'm working on his Continental now and appreciate you sharing all the steps. I did wonder about your use of concrete in the mortar. I was under the impression that the use of a clay based mortar was so that the clay bricks and mortar would expand and contract at the same rate, reducing the risk of cracking. I see Thomas did the same as you on his riserless core build. Did you give that any thought, or did you feel it was a minor issue and move forward with what was readily available and what you were more familiar with? The stove is looking fantastic... keep on keepin" on!

Thanks for the heads up, Nancy! Sounds like a heck of an adventure. I'm leaning towards Rockwool insulation applied to a sealed top plate and bottom plate in the throat and possibly lining the old firebox too. Still reading what others have done over at hearth.com... I'm assuming what they've done will be sufficient for an RMH as well.

Are you able to clean the entirety of the flex line from the top of the chimney? I won't have access to the old fireplace once the stove is built, as it'll cover the entire FP opening. I will have a clean-out so I can vacuum and clean the stove's chimney, but nothing beyond that except from the top.

I'm pricing things out now and the stainless is not easy on the pocket book. I was looking at this: DuraFlex 6 Inch 304 Stainless Steel Flexible Chimney Liner Kit - 20 Foot Length (nearly $800) but that's just single wall and I'm still not sure about the flexible line stuff. More homework to do. When I said "didn't want to make many cuts" in the pic... that was just for the first dry run stack so I could get some measurements and a visual. I'll be making plenty of cuts, just not with a wet saw. Even used ones are out of the budget. Thank you for the reply.

Jason

I'm building The Continental (big cook stove) designed by Matt Walker, with a few modifications, in front of an existing fireplace. I removed a "Better-N-Bens" inefficient and ineffective wood stove that was vented right into the firebox out of the rear of the stove. I removed the stove and hearth and cut out the old damper and will easily be able to remove a brick or two to fit a 6" stove pipe, with a couple 45's, through the throat.

I'm in the foothills of the high desert in Southern California. We have high winds that blow from every direction imaginable. Neighbor's ranch is incorrectly named Nine Winds Ranch (should be 99.) Hot and dry summers with cold and mostly dry winters that have extreme temp swings. The flue liner is 10'-6" tall, 18" x 13-3/4" oval diameter and in excellent shape (had a reputable sweep clean and inspect a few years ago.) Then two more ft to the edge of the smoke shelf where the damper was. The chimney is made of concrete block and exits the roof at the ridge with ext dimensions of 20-3/4" x 16-1/2" and is in the center of the house protruding 24" above the ridge. All exterior walls and the wall that connects the chimney to the rest of the walls are un-insulated concrete block. The attic has good insulation but is not well sealed. It's built in 1952 and has 1150 sq ft. The house gets hot in the summer and cold as crap in the winter. My sons and I got through the last three winters by wearing a lot of layers. I did install a mini-split, but after the first electric bill, it was retired except on special occasions or the really bitter nights.

The plan is to run stove pipe from the flue collar all the way up and out the top of the chimney. I will be installing an insulated block off plate at the throat and lining the back of the stove with Rockwool to keep the heat in the living space. The stove chimney is going to jut out the rear, into the old fireplace, and give the straightest shot up the FP chimney (see pic). Matt has answered nearly a hundred questions from me and has been an invaluable coach as he walks me through the build process. I've learned a lot over at hearth.com as well, but wanted to get some input from those that are familiar with RMH and masonry stoves on the best  and safest course of action for venting the stove through the existing chimney.

With all that said, is there a rocket stove scientist amongst the Permies that can guide me in choosing the proper components to get this stove off the ground and safely through my chimney? Such as: type of stove pipe: single wall, I doubt this but there will be plenty of cold starts, the chimney is short, the winds are strong and unpredictable and there may not be a substantial delta T on start ups. Double or triple wall? Stainless on some parts, or all? Add insulation in the field (a cheaper solution)? Is there a brand or company that is more trusted with quality control in selecting the stove pipe components? Is it better to use one of those flex lines to get through the throat or use 45's to clear it? Does it need to be secured to the chimney? I am next to the the San Andreas Fault.  If so, where and how often? Can I use standard ducting strap or do I need a connector made for the purpose? I assume one would be needed where the stove pipe exists the chimney, especially with my high winds. Because of the conditions enumerated above, is there a specific cap that would provide more benefits? Should I extend the pipe further out the top of the chimney to improve draft? Should I build a block off plate for the top of the chimney as well? Should it be insulated? Etc, etc...

As I put all this together in my minds eye, these are some of the questions that pop up in regards to the routing of the stove pipe and I thought they might be better answered here than anywhere else. I've searched through the forum and stumbled across threads that mention this, but didn't find where one had been documented and shared. If this has been covered, please give me a clue as to its location or, if you have done this yourself, a brief description of how you accomplished it, maybe the components used, and if it is functioning as planned or if there were any changes you'd make. I'd like to get this right the first time through and have something that is durable, functional and safe, so any guidance or advice is greatly appreciated. If there is any more info needed to ascertain the best course of action, please ask. I did my best to provide as much relevant info as I could. If you read through all that, I thank you for taking the time!

Jason