Foundation Dimension

[jachno]

Hi,

I am in the planning stages of a brick oven build, have previously built a clay oven, that has come to the end of its life.

I am thinking about building an oven with an internal floor dimension of approx 33 inches. On that basis I have allowed the following

1. 3 inches either side for the brick course
2. 1 inch for insulation blanket
3. 2 inches for pericrete insulation layer
4. 1 inch for finish
5 12 inches at the front for the entrance and chimney


Using these figures I have come to a base dimension of 48 X 60. Based on experience have I allowed enough? or do I need to change the dimensions?

Thanks

Jamie

[cannyfradock]

Hello Jamie.....welcome to the forum.

You're in the right ball bark with your figures.....but you need a tad more space. Shall send another detailed reply later in the P.M. (this evening)

Terry

[jachno]

Ok great, thank you very much

[cannyfradock]

Jamie

I hope you get lots more feedback from your first post.....here's my thoughts....

The easiest way of building the walls for a dome when building a Pompeii is cut....or chops the bricks in half (I am relating to my build.. ukwoodfiredovenforum.proboards.com/index.cgi?board=pompeiioven&action=display&thread=677 )....a normal fire-brick is 9" long. Even using reclaimed old clay bricks, they are also 9" long, so when cut in half you have a width of 4 1/2". A decent thermal blanket can be laid to just 1" but most people go for 2". I have no experience with "Perlecrete" but the minimum vermecrete (vermiculite,cement and water) should be 3" to work effectively enough to give your dome a true heat mass which will work efficiently.

The only difference is the brick depth and the vermecrete/perlecrete which is a difference of 2 1/2" combined so as everything must be calculated x 2....the overall width will perhaps have to be extended by 5" on each side....this is only MY thoughts.....hope you get a bit more feedback.

Terry

[turkey]

I double and triple calculated my base and I am still not sure I got it right, so all I will say is when you stake it out also mark the outside render location of the oven and check you can easily get to that, as I made my base right against two fences and whilst there was room for my render there was no real room for me to apply it and it was back breaking work using my hands rather than a float.

So in short, make sure you leave enough space to work when placing the base

[rokdok]

Hi Jamie,

I'm hoping to start my build this weekend, but my pompei will need to be able to be moved around.
Like your original calculations I was allowing for a 7" wall thickness-I'm sure I read this somewhere.
I'm pushed for space as the oven will need to be parked between a tree and a wall so the base dimensions will need to be 46" x 60 ", so I was hoping to get a 32" oven.
Not sure what to do now.
I'm hoping to start the wood trolley that the base is going to sit on this weekend and will stick it up under the build section.

RD

[rokdok]

A further thought.

For thermal mass if space is limited would it be possible perhaps to put the fire bricks on the base side on and maybe increase the height of the dome a bit ?

rd ps starting tomorrow

[cannyfradock]

Jamie

Just to comment on rokdoc's post........I don't agree. I would never lay fire-bricks on end unless I intended to increase the depth of fire-brick on the dome....like a Barrel/Vault oven designed to bake batches of bread.... if the oven is designed for general use i.e....pizza party's, small batches of bread, roasts etc, then fire-bricks laid flat be be enough.

I would also try to stick to the ball park figures of ..height of dome = hlaf the internal diameter, with the underside of the internal arch 63% of the dome height.

Sorry rokdoc but these main principles are important.

Terry

[rokdok]

Hi

Thanks Terry,

I'll take your advice re keeping the firebricks flat, I wasn't thinking about increasing the internal height of the dome but putting some more on top to get the thermal mass that would be lacking by the thinner walls

Thanks

RD