39 inch Corner Build

[gastagg]

Congrats JR! Looks great.

[the_dr_masuess]

You are making good progress! Keep at it and it will be done in no time

[JRPizza]

Finished the second row over the top of the arch today. Looks like I recovered from the droop in pretty good shape. I'm starting to have trouble with gravity though. Had two bricks fall when I started a new course, so have one sitting over night to set and give me something to anchor to (good advice from UtahBeehiver). I'm guessing this falling brick syndromeis pretty common from the pictures of folks using sticks to hold bricks up on the steeper courses. I have not tried grinding in the "mortar grooves" I have seen on several builds. Is that something that is going to help me finish off these last few rows? Is it time to play with my mortar? Wetter, drier, more fireclay, less sand?? I did notice that wet bricks make for adhesion problems, and I was mortaring in fresh cut ones. Maybe I need to let them sit for a few hours before I try to lay them up?

[JRPizza]

Apparently wet bricks were causing my adhesion problems. I let the freshly cut bricks dry in the Indian Summer sun and they stuck very well. Completed the third and fourth rows over the arch. I think l only have one row plus the plug left, but may end up with two rows and a tiny plug. Won't know till I get the next row in. It's starting to get foggy and damp - typical NW fall. Takes longer for bricks to dry after being cut, but the fog does nice things to the spider webs.

[JRPizza]

It's raining and I can't work on my oven without it getting soaked, so I'm starting to work on vent design options. I had planned for the vent arch to be a brick and a half long (13.5") plus 3.5 for decorative arch, but could use a little more room in front of my landing if achievable without compromising ability to get smoke up my chimney. If I build as originally designed, my decorative arch will end about 1/2 inch from the edge of my hearth. Since I have quite a bit of protrusion on my inner arch, I was thinking of doing something similar to UtahBeehiver and setting my chimney partially over and supported by my inner arch, which would allow me to go with a 9" vent arch. This would give me a 6" wide opening for my transition, and I think I could get at least 50 square inches to mate with my 8" round flue. I am planning on a 1.5" reveal, so If I make the arch a full brick tall (4.5") I will have a 1.5 inch drop to my inner arch that I'll have to make up with some creative cutting. If I want the two arches to be the same height, I would have to trim my bricks to be only 3" tall. I think the arch will have more strength with the bricks at full height, and wonder if a 3" tall brick will make a strong enough arch. Can anybody offer any advise? I think UtahBeehiver trimmed down the height of his bricks, but they were bigger than the 4.5 I am starting with.

[Gulf]

I'm assuming that you are going to include a heat break. Instead of cutting the outer arch brick down, you could go with a much wider reveal. You could then notch the outer arch to slip over the inner arch. That would allow you to complete the outer arch in the back for stability. Insulate the gap and you will have you a complete outer arch and a complete heat break. The added reveal will also give you more side to side room to work the oven.

[JRPizza]

Ah, I had not thought of that - I'll add that option while I am laying things out. I may be constrained by the width of my hearth at the front, since I am in a corner. If I go much wider I'll run out of room. I was planning a heat break though, so going over the front arch might be an option. Do you agree that cutting the bricks down to 3" tall will compromise the strength of the arch?

[Gulf]

I'm sure that if you cut them down enough, at some point, the arch would be weakened. I don't know if 3" is enough to cause a problem. I've got to dry brine 3 chickens and then fire the oven for tomorrow. I'll look at your floor plan after I get the fire started .

[JRPizza]

...... I've got to dry brine 3 chickens and then fire the oven for tomorrow. I'll look at your floor plan after I get the fire started .

Someday

[Gulf]

Sorry about not getting back last night. I was going to cook drunk chicken today for a family reunion today. I'm changing that to spatchcocks. I seem to be out of the key ingredient .

I think that it takes 12" to fit an 8" anchor plate. So, you could gain/loose 1 1/2" on the depth of the entry. A notched heat break could set it back another 1 1/2". You can go to 2 1/2" on the face brick. That is another 1". Your concrete hearth slab is 6" below the the oven floor brick. So, there is plenty of room on either side of your oven entry to place some corbels for a shelves that could be set at the oven floor height..

[JRPizza]

A lot of options and a lot to think about. I found old references to a vent photo archive, but I searched for one with no luck. Is this something that the new forum killed off?

[JRPizza]

I think that it takes 12" to fit an 8" anchor plate. So, you could gain/loose 1 1/2" on the depth of the entry. A notched heat break could set it back another 1 1/2". You can go to 2 1/2" on the face brick. That is another 1". Your concrete hearth slab is 6" below the the oven floor brick. So, there is plenty of room on either side of your oven entry to place some corbels for a shelves that could be set at the oven floor height..

My anchor plate is supposed to arrive Monday so I can start doing layouts. I have plenty of protrusion on my IA (2.5" at the bottom and ~5" at top) so I could overlap with either something weight bearing or with a notched gap for heat break. I'm planning on a heat break anyway (maybe like Russell did) but just trying to figure out if a 6" deep vent opening is going to do the trick if I make it wide enough. If six is good I can work on placement options. I like the look of the serpentine vent transition which I did a little sketch of last night. The shelve idea is an interesting one I had not thought of. My wife is shorter than I and the current height of the hearth is close to the limit of her workability, so we might try to stay close to it with just a brick or tile veneer over the top. Have not thought that far ahead yet

[deejayoh]

I wouldn't worry so much about the look of the firebrick in your vent transition. GIven that you are in Seattle, you are going to have to cover up ALL that pretty firebrick with something to protect it from the weather. It soaks up water like a sponge! Save the fancy details for your decorative brick.

I've got an 18" overhang over my entry just to keep it dry!

[JRPizza]

By "like the look" I was thinking it was more aerodynamic if that is the proper term. Seemed like it would help the flow up the chimney and make the transition from curved surface to flat mount for the adapter plate easier to build. As far as rain, I'm not only in the NW we are smack dab in the middle of the PS convergence zone and seem to get way more rain than metro Seattle. We are going to have a roof over the oven area (see my post #2) and walls on the South and West sides to block the bad weather - most of all our rain comes from S/SW. Is ambient moisture going to be a problem with exposed firebrick as long as it does not get directly rained on?

[Gulf]

JR,

Yes, a 6" opening is OK if you make it wide enough. Transitioning a smoke chamber in to the diameter of an 8" flue is not a problem. But, transitioning out to fit an 8" diameter is a little more difficult. It is much easier to make the depth of the entry to fit the 8" opening of the flue. That gives you straight vertical walls for the smoke chamber (front and back). The S Curve that you have drawn has been used by several builders to transition in to the width of the diameter of the flue. And, I don't know of a single problem that has been reported with it. I will admit that those builds that incorporated it are as "purty as speckled pups" . But, it does not allow for interlocking the corners. In my opinion completing the arch (front and back), making the strategic cuts to get the curve of the arch back to horizontal, and then proceeding with the transitioning to the flue diameter, along with interlocking the corners, is more structurally sound. It is not pretty, but I will attach a pic of how I did it. I have a lot wider entry than you, and went with an all masonry chimney so I spread the weight around the arch . So, it should not take near as many courses as mine did to get there. But, the principle is the same.

Just sayin' .