need a calculation formula

[bimfi]

I haven't taken the time to read through all of the threads on this site, so I hope I'm not rehashing someone else's comments.
I am planning to build a Pompeii oven in the Philippines. Currently I am here is the States, so it is difficult for me to plan everything. I'm looking to build a 42" dome, about 18" to 20" high. What I am looking for is some sort of mathematical formula to calculate, first: the circumference of the base layer (this is easy. Pi x D) then: the circumferences of each ascending layer based on a brick height of 2.5". Has anyone ever heard of a formula or even used one? If I were more mathematically inclined, I would try it. My reason is so that I can calculate the amount of material needed before I travel over there. I don't plan to have it built until sometime next year, so I won't be doing a lot of the actual work myself. I want to have everything ready for the contractors and laborers (wife's relatives) prior to the event. Any assistance or pointing in the right direction would be a great help.

[PIZZAMANMIKE]

Re: need a calculation formula

You might be want to purchase an oven kit and have it shipped, the cost might be the same? This way you can build the oven yourself. I also found an interesting site the other day in Germany Franks construction manual for a wood-burning pizza oven that might help you in finding other materials you can get local. Good Luck wiyh your project, Keep in Touch
pizzamanmike

[Wiley]

Re: need a calculation formula

bimfi, Being less of a math person I would think the easiest way to figure out how many bricks would be to physically draw a half section thru the center of the proposed dome in full size (since what you are wanting is a reasonable size).

You will be canting each successive layer (tilting each brick) so draw out the quarter section of your elipse, and then with dividers strike off 2 1/2" cords (portions of the arch) to get your new radius for each layer. Once drawn it wouldn't be that many calculations.

Of course, the entrance will subtract bricks from several layers. And then too you will have to compute the bricks required for the entrance and transition to the chimney. And add the bricks required for the hearth. And probably including some safety factor for broken bricks and cutting mistakes since getting replacement bricks might perhaps be difficult.

Hope this helps,
Wiley

[masuzzu]

Re: need a calculation formula

Is it necessary to make angle cuts for the dome?
Can the dome be built by using standard rectangular bricks?
Which is the better approach?

[Ken524]

Re: need a calculation formula

Masuzzu,

You can take standard firebricks, cut them in half and build the dome from those. We have many ovens here that have been done that way.

It is definitely not necessary to make angle cuts.

[david s]

Re: need a calculation formula

How about calculating the area of your hemisphere and divide it by the area that will be covered by a brick = no. of bricks required.

[Archena]

Re: need a calculation formula

Hi, I found this thing online - maybe it can help.

Brick Construction Calculator


Surely someone around here is actually done this before. I never have, and I'm not planning to build with brick anyway, but I would think that you would need to take in account the reducing diameter of each course. I'd probably figure it as each course being an individual circle - but the only time I passed calculus was when I was too sick to know what I was doing so you might not want to go by me...