Hearth size

[JRPizza]

Great! Just left you a PM telling you how lame this all makes me feel ;-) Looking forward to seeing what you recommend.

[Gulf]

I can't see your side view for some reason. You may add it in an edit. I will take your new oven dimensions and do a full scale on the freezer after SWMBO leaves for work tomorrow . Don't sweat it, there is a solution.
EDIT: I can see the side view now. I would rather do it full scale. I will let you know what I find.

[JRPizza]

[JRPizza]

Here is a side view with the brick all the way back, like my left hand option, that shows at the center of the arch my 9 inch brick will leave a gap. If I move the bricks forward I'll get a bigger gap, so I am more confused now than I was before. I tried reading some posts on opening details, but the links are still messed up.

[JRPizza]

My current plans are for a 39" oven. That should allow me to put 2 24X36 inch ceramic boards together and have insulation come to the outside of the dome @ 48 inches. The FB plans put the door height at 12 for a 36" and 12.5 for a 42", so I was going to shoot for 12.25 as close as I can make that happen.
You have a pretty keen eye - my cad program tells me that the option at the left gives me a 2.4 inch thick brick at the entry, which for my plans about 1.5 of that would be exposed on the entry side. The option on the right shows about 5 and a quarter inch (5.27) so that is over twice as thick. If I split the difference I Get around 4", which puts the centerline of the brick on the outer dome circle. I'll see if I can get a side view done.

[Gulf]

I think that I would choose something in between. The option on the left has the bottom arch brick only about 2" thick at it's shortest point. That is an area that you will be pushing an insulated door up to. I think it needs to be a little thicker there. I don't think that I would let it get any narrower than 3.5" at that point. The one on the right is already at the intersection of the inner diameter of the dome. The dome will pull away pretty fast from it with each course. That is just a little forward from where my arch is laid out. But, I had to extend the top 4 courses of my arch to make it work. Also my dome and arch brick are 8" brick.

I just did a rough full size profile of a 36" dome and with an 11.75 height entry. It doesn't appear to me that even a 9" brick would have enough reach without extending. I would have thought it would. I may have missed something, I will look at it again. Try drawing the profile in sketchup and double check me. Maybe someone else will weigh in. But, there is always the squirrel tail fix.

I don't have sketchup or any other program. I use Microsoft PowerPoint (not to scale) to bring out details sometimes. I do most of my scale drawings with an old drafting set. For the full size profile of the entry I mentioned above, I will need to clean the top of the chest freezer before my wife gets home .

[JRPizza]

Gulf, on first brick placement, I am showing two options, the brick on the right was my original, where the innermost face is tangent to the circle representing the outside of the dome. The brick on the left has the outermost face tangent to the outside of the dome. I was thinking of building the arch like the left brick if that is not too far back. As a retired airplane guy, I like the idea of indexing the point of the brick to some feature rather than having it float between, unless there is a reason I should pick something between the left and right views. Any suggestions? Also, what program are you using - is it sketchup? I am using freecad since I have it and use it to make models for my son's 3D printer.

[Gulf]

Yes, I used the IT to mark my cuts. But, I set my inner arch too far forward. I had to splice the upper four inner arch brick to extend them in to meet the inner curve of the dome. I don't really advise that. But, it is not near as difficult as compensating for extending the dome courses out to meet the arch. I did not get many pics of that part of my build. I was too busy scratching my head and "sweating it" lol. I did complete my arch first, but I tied it in with a couple of courses of the dome brick at the bottom. If it is not tied in, it will fall over to the inside under its own weight. Below are two pics. The first is of my arch. Though, they are not completed courses, you can see where I laid enough of the bottom two courses to keep it from falling. The second pic is of Kbartman's. KB, built his arch as he laid his dome courses. You can see how he tied the arch and dome in in at the bottom. You can also see a very good example of another trick on the inner arch to make the cuts for the dome brick a lot easier.But, that is not important right now to get the foot print of your oven for the template.

[JRPizza]

Gulf, I notice you built your inner arch first. Did you use an IT or similar tool to help you "widen" your arch as it gained height? Is that what you meant by having the arch a full brick into the dome? It looks to me like on some builds they just used a constant arch thickness all the way up, and had to compensate for it with some tricky cuts.

[Gulf]

On your original drawing, your reference line for the face of your inner arch protrudes about 1.5" to maybe a full 2" from the outside of the dome. It doesn't have to protrude any. But, 1/2" to 3/4" is fine. It looks to me like 1/2" to 3/4" would bring it to about the inside diameter line of your dome at the floor. Look at the green dotted line in the photo below. On the backside of your cardboard template, you can do a full size profile of the inside arch and the inside curve of your dome to see how far the inner arch will reach. Don't sweat it, though. Having the inner arch reach full length into the dome just makes it a little easier later on in the build. There are plenty of inner arches on this site that don't. Probably, most of them. I hope this helps.

EDIT: I think that you edited your post after I started working on the reply. But, I think that my answer clarified that anyway. If not let me know.

[JRPizza]

Thanks Gulf, firebrick it is then. I'm drawing a full size template on a large piece of stiff cardboard. I'm a little puzzled at your comment about setting the first inner arch brick. I obviously don't want my arch to be bigger than one full brick at the top, so how do I know in advance where to set the base brick? Looking at your mod to my picture, do I set the outside corner of the first arch brick to intersect the circle representing the outside of the dome? On on my full size layout, that lets me move the arch back almost 2 inches. Does that sound about right?

[Gulf]

I recommend firebrick for the entry. The rear and upper section of the entry will receive extreme temperatures. The lower and front of the entry will not. If you go with a "common brick" make sure that it is a true clay paver. A clay brick made with no other material in it. And definitely, make sure that it is not a concrete paver. Not all commons are the same. Since you are sweating this as you say, I think that it is time for a full size template drawn on poster board.

[JRPizza]

Thanks for all the help. I am sweating this as I want to keep as much room in front of my stand as possible. My next move is to cut the backer board at a 45 degree and want to make sure I have enough room without too much sticking out. A question for you all - did you use common brick for the vent arch or firebrick? Looking at pictures it looks like folks have done it both ways. I believe Forno recommends using common bricks which would seem to be more durable if the heat resistance is not needed. Since they are different dimensions which brick I use will change my landing size.

[Gulf]

I agree with Randy about the wider reveal. The wider, the better, imo. Build the reveal real wide enough, and it will offer the working room of a "flared entry" without the "intimidation". My reveal is 3".

I show the inner arch width at the base @ 28" assuming these are half bricks sitting on edge.

That is partially true, but the inner arch brick are not exactly "half brick". Their length is determined by the distance from the vertical outside face of the arch to where they intersect with the inside curve of the dome. That distance will change depending on how high the arch brick is from the floor. They should reach further into the dome from the vertical face as the arch gets higher. At the very apex of the arch those brick will be very close to a whole brick in length. From your drawing it appears that you need to shift your inner arch back a little to make that work. It will also give you a little more room. I think as much as 1.5".

Also, leaving a little reveal on the decorative arch will allow for an easy to fit storm door. I'm not sure if you are including any type of heat breaks in your build. but, do consider a space behind your decorative arch.

[RandyJ]

1" will work for the reveal but you might be happier if you went up to 1.5" that just gives you a little more room to work and makes it a little easier to get a door in and out. So if you can find the room it would be a good idea. Other than that I think you have a good plan. You are pretty much laying it out as I did. We'll except for the part where I just eyeballed where I thought the oven should sit and went from there.

Randy