My first attempt for 42" oven / changed to 36"

[George_M]

Hi,
Soon i will start my first atttempt to construct a 42" oven and if all goes well i will make more 2-3 ovens for my brothers.
So,i have some questions to be sure that all the steps will be correct before start to make the oven.
I read lot of topics releated to 42" ovens and as for the stand i saw that some used 4 concrete blocks in vertical and 3 horizontal and others used 5x4 bricks.
But which is the correct?

Also,each layer of concrete blocks need to fill the cores with cement or only the last layer need cement?

Thanks all who shared photos!
I will do the same when i start my construction.
Regards from Greece
George.

[leetheldc]

re: My first attempt for 42" oven / changed to 36"

Hi George and welcome to the forum your in good hands here you will get lots of help to all your questions from all the helpful folk as regards to the block stand there is no correct way really it just needs to finish at the right height for you most go with elbow height as a finished level for counters etc. so it's just a case off finding your own counter height and working down from there. For strength it is best fill all 4 corners of the blocks with concrete and re- enforcing rods through the cells I just filled all mine as I don't take to long and it gave me a solid base for the slab some just fill with rubble or empty cement bags and just cap the top off either way is fine hope this helps and good luck!

[leetheldc]

re: My first attempt for 42" oven / changed to 36"

I just looked back at my pics and remembered I filled every other cell the others got filled when I poured my slab to tie it all in My memory is rubbish ! You can see it here http://www.fornobravo.com/forum/8/7-...t-20707-2.html

[George_M]

re: My first attempt for 42" oven / changed to 36"

Nice to meet you!
Ok i measure my space and i start the constrcution,yes the corners will be filled with concrete,you are right.
I will be back with photos,i hope the weather will be sunny to start soon my oven!
I will read your topic now.
Thanks for your reply.

[George_M]

re: My first attempt for 42" oven / changed to 36"

I saw your topic and you put calcuim silicate board as floor insulation.
How does it cost?
I think to use common cement + perlite if it's correct for insullation,but if the silicate board is cheaper i will put this.
I would like to read some suggestions about this.

[Tonyp]

re: My first attempt for 42" oven / changed to 36"

Ceramic board is excellent but cost more. The trade off is you can use less thickness to achieve the same insulating properties. Plus it's pretty easy to work with. Cement with either perlite or vermiculite will work fine but must be much thicker, 2-3" vs 5-6" for the latter. There is also a lot of moisture within the cement based choices which takes a while to dry.

[George_M]

re: My first attempt for 42" oven / changed to 36"

When you say 5-6" for latter what do you mean Tony?

[Tonyp]

re: My first attempt for 42" oven / changed to 36"

Hi George,

Sorry I should have explained better since you are from Greece. Great place, spent 2 weeks on vacation there last Summer and had a fantastic time!

The Perlcrete or vermicrete both require 5-6" thickness minimum to achieve proper insulation value. I think some have gone as thick as 8"

[George_M]

re: My first attempt for 42" oven / changed to 36"

Nice Tony ,which place of Greece did you visit?

I will use second frame in the center of the base and i will fill it with cement and perlite in thickness of 8".
The thickness of cement base 5-6cm (2") is good or need more?
Today i will collect the materials for the stand.
Thanks for the explanation.

[Tonyp]

re: My first attempt for 42" oven / changed to 36"

Nice Tony ,which place of Greece did you visit?

I will use second frame in the center of the base and i will fill it with cement and perlite in thickness of 8".
The thickness of cement base 5-6cm (2") is good or need more?
Today i will collect the materials for the stand.
Thanks for the explanation.

Hi George,

We spent a couple days in Athens then took a 4 day taxi tour which included Corinth, Olympia, Delphi, Meteora then back to Athens via Thermopylae for a ferry to overnight stay on Santorini.

When you say cement base you mean the slab supporting the insulation and oven? If it is to span the block wall without any center supports then the usual method is I think 5" thick with 1/2" rebar at a 12" spacing.

[George_M]

re: My first attempt for 42" oven / changed to 36"

My plans is to make a base like the photo.
The minimum height for the perlcrete will be 5"
The height of the cement with the questionmarks how should will be?
(i take the photo from other topic)

[Tonyp]

re: My first attempt for 42" oven / changed to 36"

Hi George,

You could certainly surround the perlcrete with regular concrete as long as your perlcrete section is large enough to put the floor and dome entirely on it. As for how thick the surround is, would be up to you. It depends on how you plan to enclose or finish the outside of the oven and it's supporting base. I guess for simplicity you might make it flush with the top of the perlcrete? If you plan to enclose the dome completely in a small framed structure you wouldn't need to fill in that extra space at all really. Although I hear the perlcrete is fairly fragile so having the edges protected doesn't hurt.

There are lots of ways to go about designing and building a well functioning WFO. The choices are up to you. One of the things I did was go through lots of build threads as well as the photo albums on the website to look at different ways to finish the outside, different materials used, and arch shapes etc.

[Greenman]

re: My first attempt for 42" oven / changed to 36"

I used 4" concrete slab and then formed it up another 4" with a 'keyhole' formed in this to accommodate the oven and entry gallery. I poured the outside of the keyhole and then filled the centre with 4" of vermicrete. It worked for me. A hole drilled in the middle of the base slab will allow moisture to escape if the hearth gets drenched some time in the future.

The pictorial details are in the build thread.

Good luck with your build. It is a job well worth the doing.

[George_M]

re: My first attempt for 42" oven / changed to 36"

Good idea,i will read your topic.
Thanks!

[Rbhumbert]

re: My first attempt for 42" oven / changed to 36"

George,

I did an apron along the lines that you are considering. I cantilevered it so it would fit the dimensions of my brick enclosure and it made a nice transition to the stone below. Many ways to do it to make it your own.