Locating the arch????

[UtahBeehiver]

Have you downloaded the free eplans from Forno Bravo? They provide a good but dated baseline for WFO oven design and function. There is a table that shows the door heights for both low and high dome ovens 36 and 42. Other diameters use a rule of thumb is 63-65% of dome height for arch and width is more builders need and discretion. Down load plans and study it answers bulk of builder's questions

[Chops]

Hello! Is there a Guide, as to how High & Wide, an Oven door should be ? in reference to your oven's Diameter ?

[Sharkey]

Re: Locating the arch????

Wow you have a great location for your oven. Do you have any wider angle views of where it is? And how are you planning to finish the exterior?
Chip

Thanks Chip. Here is my build thread.

I keep changing my mind on how I'm going to finish it so I haven't done any work on it for a couple of months but it is cooking great pizza and bread.

[mrchipster]

Re: Locating the arch????

I load tested my arch with a bit over 100kg (220 pounds). No problems.

Other than a hemispherical arch being inherently strong I think the arch being tied into the dome well prevents spreading too.

Wow you have a great location for your oven. Do you have any wider angle views of where it is? And how are you planning to finish the exterior?
Chip

[dottavio]

Re: Locating the arch????

I'd like to thank Cheesecake for starting this thread. You saved me a ton of grief and work. I had not thought about the placement of the arch inside the dome. I only measured the opening and height.

Since reading this post I have re-designed my opening. During the redesign I noticed that the distance of the arch from the center of the oven is dependent on the curve selected. The closer the arch is to the center the wider the horizontal opening which must be compensated by the arch side walls.

I am building a corner oven so my landing will be longer due to the diagonal of my stand so I needed a longer oven landing. In the attached you'll see the two versions of the 44" oven (round and oval). The oval will be more like the Neapolitan style even though the dimensions make it more of a hybrid. Using the oval I have a opening to height ration of .63. The 44" Premio2G has a ratio of .65 so I should be OK. I think I'll cut out some cardboard templates as a double check.

I laid out the floor last weekend and I will start the dome this weekend.

Hopefully all my readings in this forum will help me avoid more major mishaps.

[GianniFocaccia]

Re: Locating the arch????

Arched openings offer no practical advantage and several disadvantages (such as increased complexity in fabricating a door and the spreading of the arch over time

The advantage for me was the straightforward transition construction. I feel it was much easier than making and tying in the complicated frontal dome brick cuts required to fit a rectangular 'arch' or the traditional straight-sided shallow inner arch as called for in the FB plans.

Neil I am not sure why you say arched openings will "spread"

This is because true arches inherently exert side thrust. Practically speaking, I can't see an oven's inner arch spreading (ever) as long as it is properly tied into the mass of the dome. To me, the hemispherical arch has centuries of proven strength, clean symmetry, and was fun to build. Much more work than dropping in a piece of angle iron, but well worth it.

[Sharkey]

Re: Locating the arch????

I still cannot in my mind come up with a stronger brick built design than an true hemisphere.

Chip

I load tested my arch with a bit over 100kg (220 pounds). No problems.

Other than a hemispherical arch being inherently strong I think the arch being tied into the dome well prevents spreading too.

[mrchipster]

Re: Locating the arch????

Arched openings offer no practical advantage and several disadvantages (such as increased complexity in fabricating a door and the spreading of the arch over time).

Neil I am not sure why you say arched openings will "spread" if the opening is a true hemisphere it should be self supporting and free standing. No spread should occur. Unless you are considering the weight of the chimney to be a significant stress factor on the arch which it may be.

I still cannot in my mind come up with a stronger brick built design than an true hemisphere.

Chip

[Neil2]

Re: Locating the arch????

Buy some cast angle iron and make a rectangular opening.

Arched openings offer no practical advantage and several disadvantages (such as increased complexity in fabricating a door and the spreading of the arch over time).

[david s]

Re: Locating the arch????

The wider the arch the greater the heat loss, but the access to the oven is improved.

Generally the wider your arch is the greater will be the area that is presented to the outside, given that the height is fixed. It will be the frontal area of the arch that will lose heat through radiation and the fact that doors don't insulate as well as the insulated floor and dome. In my case of a small oven the doorway is a larger percentage of the oven area. This is one of the main disadvantages of smaller ovens.

[GianniFocaccia]

Re: Locating the arch????

I cant see opening width being a factor, height yes.

Within limits, I agree, depending on arch geometry. One can see in the diagram below that a hemispherical arch that is moderately wider than a vertical-sided arch would still retain more upper-dome heat. I would not define smoke/hot-gas exhaust as heat loss, rather a function of the normal aspiration of an oven based on its inner-arch geometry.

Further, the frontal profile of the hemispherical-entryway suggests that it may create an easier task to merge the dome to the inner-arch. Granted, per the FB plans, the vertical-sided inner arch is less daunting in its initial construction requirements, but IMHO, I believe the hemi-arch solves many transition problems (including arch location) and results in a stronger, symmetrical arch that requires no buttressing.

John

[Paul in Rockwall TX]

Re: Locating the arch????

For what it's worth, my dome is 39.5"W at the bottom, dome Height 19.5", opening width 19" and opening height 12". As you may be able to see from the attached, I used a dome template made of plywood. It allowed me to radiate from the center point of the floor to see how the dome would progress from any angle. I just set the inner arch where I wanted it to intersect with the dome, if that makes sense.

PhotoPlog - Dome and Floor

[david s]

Re: Locating the arch????

The wider the arch the greater the heat loss, but the access to the oven is improved.

[brickie in oz]

Re: Locating the arch????

Is it more difficult than that?

Nah thats it.

Underside of arch to intersect the underside of the dome no matter the size of oven or arch.
If you mess with 1 dimension you have to mess with the other.

I cant see opening width being a factor, height yes.

[Cheesesteak]

Re: Locating the arch????

one would think, though, that there would be a good, approximate location for the arch. Given the relatively standard oven opening (for the 42" Pompeii) - the intersecting point should be pretty standard. At least it would get you in the ball park.

okay - I haven't messed with SketchUp in a while - I just downloaded it and threw this together. Does this look right? 42" radius dome, 20" dome height, 12" arch height. The inside edge of the arch should be 4 1/2" inside of the inside wall of the oven. That would make the top of the arch meet the inside edge of the dome where they intersect.

Is it more difficult than that?