dlebla's 39" MA build

[dlebla]

Hello,
Okay, so my summer honey to do list has just about been completed and am now ready to start my build. I have attached a few drawings of what I'm planning on doing, if anyone sees any issues or suggestions please let me know. I will use steel studs and cement board to close it up, but this is not finalized. I do have a few questions to start,

1. Being in MA should I be concerned about starting and not finishing before winter arrives? Do I need to winterize some how?

2. Planning on a 39" oven, with a 64" stand. Add in the brick thickness, steel studs, and Cement board it gives me about 1" clearance. I have seen others who have cut the steel stud laying down at the tangent point to create a little more space if needed. So the question is, am I cutting this too close? Should I make the stand wider? I have the room to do so, but the smaller the stand the better. Thought?

3. Trying to figure out where the door should be, locating the arch. Do I have this correct in image?

4. I have drawn the flare for the entry. How much wider should it be? Any rule of thumb?

5. I would like to use an IT, I have yet to create one and will not be able to weld one. So I need to do some searching on how to create one, unless someone has a 39" IT they are done with and would like to pass on.

All help/Input is greatly appreciated as I have ZERO experience in any of this and am eager to start/make changes. I have been amazed at others who have had no experience and I will be happy if mine comes out half as good.

Fire Away....

[dlebla]

Re: dlebla's 39" MA build

How do I get the images to show in the bottom instead of the file names? Thanks

[Laku]

Re: dlebla's 39" MA build

Don't post them as pdf. Use .jpg, .gif or .png instead.

[vtsteve]

Re: dlebla's 39" MA build

For row #4 of your stand, you can repeat row #2 (and lay an extra rebar in the slab across the opening, just for peace of mind). There's almost no load at the front, and access is a lot easier if your front is open all the way to the slab.

If you set your studs so the widest point of the dome falls between studs, it frees up another 3 5/8" for insulation blanket - assuming your FB/vermicrete rises above the bottom channel.

[GianniFocaccia]

Re: dlebla's 39" MA build

2. Planning on a 39" oven, with a 64" stand. Add in the brick thickness, steel studs, and Cement board it gives me about 1" clearance. I have seen others who have cut the steel stud laying down at the tangent point to create a little more space if needed. So the question is, am I cutting this too close? Should I make the stand wider? I have the room to do so, but the smaller the stand the better. Thought?

Factor in at least 3" of insulation between your dome and steel studs. Insulation is critical to oven performance, especially on top. If you only put in 2" of ceramic blanket, you can fill the rest with vermiculite/perlite.

3. Trying to figure out where the door should be, locating the arch. Do I have this correct in image?

Smart of you to consider this before you start building - this will save you time and aggravation later on. Take a look at the photos (worth a thousand words) hre for my approach. Post #34. http://www.fornobravo.com/forum/8/octoforno-7122-4.html

4. I have drawn the flare for the entry. How much wider should it be? Any rule of thumb?

If you are planning on incorporating a heat break, just make sure you have enough room for your inner and outer entryway arches to smoothly flow up into your flue. A flaring entryway is a little more complex to construct (out of brick) but you will thank yourself for the flare every time you use your oven.

5. I would like to use an IT, I have yet to create one and will not be able to weld one. So I need to do some searching on how to create one, unless someone has a 39" IT they are done with and would like to pass on.

You can make an excellent IT out of wood as others here have. I didn't use an IT since my 39" dome is not hemispherical. (It's slightly flatter with higher 'shoulders'). I went with the dome template shown in the pics.

Good luck and post lots of pics.

John

[dlebla]

Re: dlebla's 39" MA build

Thanks to everyone who replied back.

I think I will repeat row 2 on Row 4, I think a little extra room getting in there might be useful, I thought this might be a structural problem.

I plan on being above the bottom channel, I think this this extra space will give me plenty of room and alleviate concerns about being too tight on the stand. I never thought of that, thanks.

I have 3 boxes of #8 smart wool 607 by thermal ceramics. 50sq ft per box. I'm hoping to get 3" out of the 3 boxes, I can get more for $65 a box if needed. Not sure if I will top off with vermiculite/perlite yet.

Gianni - I think I understand your pics about locating the arch. I'm hoping that this will become a little more clearer for me as I start working with the bricks and have a better picture in my head. I have been thinking about this for about 2 years now so I have had a lot of time to think about it. I see you have a heat break, I'm not sure if I want to do that or not. I'm planning on placing the FB board under my entry. Placing the heat break between the oven and entry does not seem to hard, I assume the advantage is more retained heat, but how much? I assume you would still have the FB Board under the entry.

[dlebla]

Re: dlebla's 39" MA build

Here is an additional attachment with some dimensions as well as the others in .jpg format.

[GianniFocaccia]

Re: dlebla's 39" MA build

dlebla,

You have the right dimensions for the inner arch and it's distance from the center of the oven. Just note that the minimization of dreaded droop is a function of the amount of curvature you can create in the top of your arch itself and the first course above it. I'll try to post a pic that illustrates this when I get home.

Yes, the heatbreak is a solution exclusively dedicated to reducing the loss of retained heat as much as possible. A connected entryway, floor and flue all add surface area (much it exposed) that act as a heat sink drawing heat away from the oven.

If I read your plans correctly, you have a total of 32.5" from the front of your oven stand to the inside of your oven. This creates a 6' reach to the back of your oven. I would seriously consider reducing this as much as possible. Your back and arms will thank you every time you look to add/move wood in your oven, not to mention heavy pots and hot ashes.

[deejayoh]

Re: dlebla's 39" MA build

Check out my dome spreadsheet calculator for your IT length. Should also help you with brick order

http://www.fornobravo.com/forum/f28/...tml#post135618

[dlebla]

Re: dlebla's 39" MA build

Thanks for the spreadsheet, I have downloaded it and will try it out shortly and see what it comes up with, looks very handy!

Gianni - I would love to see a picture of the droop you are referring to. I have noticed a teardrop shape on some other builds, which I thought was a result of the arch being too far out. Is this what you are referring to?

I have been thinking about the heat break and am going to look into it further. I'm thinking of doing something like this, see attached. I'm thinking of cutting in a square channel into the bottom of the bricks just outside the inner arch and fill it with some of the FB board I will have left. I will leave the top of the bricks continuous but this should slow down the transfer of the heat. I could easily do something similar on the sides and top, I think. Not sure how much brick I should leave for strength but this is my initial thought if I was to add it. Thoughts?

I think your right about the depth of the oven. I'm not sure where I can cut back though. I have read you should have a 12" landing in front of the oven, and I have left 16" between outside the inner arch and the outside of the outer arch, did I say that right? I will have to look into other build and see what others have used for this dimension. I'm going to use 8" pipe for my chimney. So I think I have designed this to the standard. Should I notch my landing in front of the oven and sacrifice there? Maybe about 6" ? DO others find this space useful? Wasteful? I know I will get used to whatever I have so others advise here would be helpful.

Thanks

[dlebla]

Re: dlebla's 39" MA build

Now that winter is over I'm back in oven mode. I have made some changes to my plans based on some feedback here and have finished the block stand. I have the supports up and am ready to pour my hearth. Since I started with a cement slab that was existing, this will be my first time working with concrete. That being said I just wanted to run few a few things and please correct me if I'm wrong so I do not make a stupid mistake, I will make enough through this project.

1. I have all the rebar and supports underneath in place.
2. I'm going to get a U Haul Cement cart from a place about 20 min away.
3. I will fill every other core and the hearth.
4. Once filled I will use a 2X4 to screed the cement level after I Shake the rebar and bang the sides of the form to get all air out and to aid in the filling of cement.
5. Once Level I need to float the entire thing with a wooden trowel

I do not have any cement tools except a straight edge trowel, I plan on building a cheap wooden trowel if needed. Is there any other tool I will need to make or buy for this?

Is that all I need to do? Being in Mass the weather is going to be between high 60 during the day and a low of mid 40's at night. Do I need to worry about watering or covering the slab? I'm going to the library for a book on this but I would feel better getting directions/insight from someone here that has done this. As always thanks for the help and am looking forward to posting some pictures soon.

[UtahBeehiver]

Re: dlebla's 39" MA build

Hey Dlebla,

I can't remember for sure but I think you gave you either my IT or brick jig or both, so you are finally goint to be able to use them. When you done send them on to some other WFO builder.

Are you doing an enclosure or bare igloo? If and enclosure, most of your concrete finish will not been seen if an igloo the finish may be more visible but depends on what your final surface will be. In any case the most importart part is a level surface with no low spots around the dome area for water to pool. Perfect weather for pouring and curing concrete.

[david s]

Re: dlebla's 39" MA build

Hey Dlebla,



Are you doing an enclosure or bare igloo? If and enclosure, most of your concrete finish will not been seen if an igloo the finish may be more visible but depends on what your final surface will be. In any case the most importart part is a level surface with no low spots around the dome area for water to pool. Perfect weather for pouring and curing concrete.

If doing an igloo it's actually a good idea to mound the supporting slab up slightly in the middle and slope it down to the outside so water will not be encouraged to find its way under the floor.

[dlebla]

Re: dlebla's 39" MA build

Utah - Yes I was lucky enough to get your fine tools last year and was unable to use them as I ran out of time before winter. Now that the weather has turned I'm ready to pour my hearth slab. I plan on building an enclosure not an igloo. That being said pour the cement, screed with a 2X4 and then just trowel it smooth?

I will definitely pass on the tools you were so grateful to pass on to me. Cant say it enough, Thanks!

[dlebla]

Re: dlebla's 39" MA build

So I poured my hearth about 2 weeks ago and will be starting soon. I have my FB board and the bricks will be arriving next week. I'm undecided about a Thermal Break, how easy is this to incorporate? The floor seems rather easy to incorporate, but the rest seems to be the real challenge. On one hand I'm thinking just keep it simple and on the other I say go for it! Any suggestions or thoughts?