Help with vent floor size

[Les]

George,

I think we are mis-understanding your question. I interpret it how much space you need from the dome opening to your landing area. If that's the case, here are my numbers.

I have 12 inches of landing area. I am allowing 4 inches for decorative brick. My front arch brick is 5 3/4 inch, the vent opening is 6 inches and the back arch is 4 1/2 inches. All said; from the front of the landing to the inside of the dome will be 32 1/4 inches.

Les...

[biondoli]

I added Les measurement to the picture he has on the web so we can graphically confirm our understanding and use as guide. Hope this helps, check the link below.
Carlo

[james]

That's it.
James

[dmun]

Originally Posted by asudavew

Here is a quote from this link:
The Chimney

Here is another quote from that link:

masonry chimneys need a foundation that extends below the frost line, which is a few metres below grade in most of Canada.

A few? Two? Three? Half a dozen? Hell, why not dig down to bedrock?

[Les]

I hear ya David - and THAT's funny!!! I think what they are implying is that two feet short of magma is best...

Les...

[Les]

Carlo, extremely helpful to add the picture to it. Just to add some clarification, I have 4 inches between the landing and the existing front arch. My landing begins at the front of the hearth.

Les...

[RTflorida]

A few metres??? Seriously, that sounds like it came from the arctic circle foundation guide. I'm originally a northern boy, 3-5' frostlines I am familiar with.

To me "a few" means 3 or 4 = 9-12'.....good golly, its gotta get damn cold and stay damn cold (arctic circle???) for far too long for my tastes. Does the ground ever actually thaw completely?
Maybe 10 years away from cold and snow has affected my memories and what I thought I knew. I'm just amazed by an inhabited area having a "few metres" frost line.

[gjbingham]

Great response guys. Carlo and Les caught my original concern and the responses confirmed the answer I came up with. I'm way past the point of no return now (barring a complete collapse). I've opted to build the dome first and deal with the vent and oven opening later.

The recommendation for a 4 X 8 vent was also interesting. I was lying in bed last night thinking that it might help increase the draw of the oven by making the arch of the oven opening slightly lower, say a half inch or so, than the height of the vent. From the decorative arch in front of the oven to the anterior edge of the vent, build the arch 12 inches or so high. The actual vent itself framed in at 12.5 inches back to the oven dome opening.

I'm not sure if this is a clear description. Maybe it's a dumb idea. It seems like a slight rise in arch height from the oven opening back to the actual dome would speed the draw of the chimney and minimize smoke sneaking out the front during the early heating process.

[christo]

I made my decorative arch about an inch lower than the vent arch - even lower a the edges to accomodate my lights.

I'm not sure if that is why - but I have no soot on the front face of my decorative arch after at least 12 fires......



I beveled all of the bricks at 45 degree angles leading into the opening for the vent. It could also be the really cool teracotta vent transistion idea I stole with pride from DMUN Dave....

Good luck!

Christo

[Les]

making the arch of the oven opening slightly lower, say a half inch or so, than the height of the vent.

George - that's what I have planned, I'm lowering my decorative arch to accomplish this.

Les...