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

[George_M]

Hi,
I need your help for the first arc.
Which size for the bricks is ideal for the first arc?Half or full brick?
Any ideas or photos i will appreciate.
Thanks

[George_M]

Tomorrow we will make the entrance arch.
I think all goes well so far..

[George_M]

[George_M]

Progress update!

[deejayoh]

ah - 5-6 meters height. I didn't see that. At that height, David has a good point - bends are likely a non-issue. I was envisioning something shorter w/ more acute angles to the bends. Six inch is likely fine and will save you a lot of $$$

[George_M]

Ok i will get 8".
Also,i need to know the chimney opening in the arc before the flue.
Is it standard dimension?

David,i plan to do like the oven in your first photo.

[david s]

If your flue is around 5-6 m tall it will more than compensate for the bends IMO. Attached is an oven with such bends and it draws way better than the same oven with a shorter flue of the same diameter.

[deejayoh]

For a 36" oven, 6" is standard. But that is for a straight run. With 2 elbows you will slow velocity. I would buy 8" to be safe.

[George_M]

Any ideas?

[George_M]

I run out from bricks and i will go to buy some and i will buy chimney base.
How to calculate the correct size so the smoke go inside the chimney and not running out?
I found this calculator https://community.fornobravo.com/for...lculator/page3
and i need your help to calculate the correct size.
My idea is to send the chimney back from the oven with elbow and with a second elbow to go up over the roof.
Total height from the oven to final height over the roof is 5-6m.

[George_M]

Thank you david for your interest!

[david s]

Ah, ok that's good. By the look of the colour I thought it may have been Portland cement and sand only.

[George_M]

George, your mortar looks very dark. Have you added lime and clay or are you just using sand and cement?

David,I use calcium aluminate cement with chammotte (sand from bricks) 1:3 .The store where I bought it told me to use this ratio without lime,only this..
This is not Portland cement .

[George_M]

Don't want to burst the bubble but it looks easy but will be much more difficult than it seems. They are very complex angles and difficult to do. But it is your choice.Research tapered arches and look how smooth the transitions can be.

Hmm..I will think it again to do like this.

[david s]

George, your mortar looks very dark. Have you added lime and clay or are you just using sand and cement?