questions before starting

[pfunk]

Sorry my first post got sent before I was done.
I've downloaded the guide, read through it, feel confident in my brick cutting / laying abilities and ready to start the adventure!

Here's a couple questions, I'm sure I'll have a couple more.

1. Any thoughts on building an oven with a smaller floor than 36" diameter. . I've definitely seen earth ovens with 24" inside diameter and they worked great. I feel like everything I've read gives me confidence that you could build an oven of any floor dimension (within reason) but the inside ratio of inside height to floor will be different because the brick size is the same. Just want some thoughts on "acceptable" dimensions based on people's experience.

2. I don't understand one picture in the plans . Figure 8.1 ... the angle iron framed opening. I see some other threads about the opening but I'd like to see other photos of that from different perspectives to really understand what's going on there.

3. Is the 2" thick insulation board just needed under the cooking floor? Is that easy to cut with a circular saw or jig saw? Does that need to be embedded in concrete? Or could that literally sit on top of an existing outdoor concrete countertop that can support the weight?

That's all for now. Thanks!

pf

[SableSprings]

Welcome to the Forum! My thoughts on your questions:

1) David S has a cast oven that's about 21"-22" inside diameter (sorry, I don't remember offhand the exact dimension...but it's much smaller than most builds on the site). He does fairly large pizza party "productions" and shows that with experience and planning, a smaller oven works fabulously. You should take a look at his build thread. TinyURL to David's build thread is https://tinyurl.com/y5bsr6qy For most smaller ovens, it seems to me that casting is the predominant method. Most brick ovens seem to be in the 36" range. Mine's 39" and I'm very happy with it. David points out that the smaller the oven, the less wood & time it takes to get it up to pizza temps. Larger ovens do take longer to heat up and obviously more wood...but you do get more retained heat to do more cooking and baking over several days. So the size of your oven is dependent on 1) What you are planning to cook/bake, 2) How often you are going to use the oven, & 3) How much room and money are you willing to invest.

2) I did an angle iron top opening (rectangular) for my oven rather than an arch. It just seemed simpler to me and at the time it was a popular (and easy) way to do the opening. I liked the rectangular opening as well when I was looking at having a fire/baking door done for the oven. You might get some of those different perspectives from my build thread & pics (also covered a little bit more expansively in my blog).

3) The current convention is to drill some 1/2" holes in the concrete slab (hearth) under the future oven footprint. Lay some porcelain tile pieces (or scrap mosaic tile sheets) on top of the slab, positioning the gaps between the tiles to "guide" water/moisture to the weep/drain holes. Next you place the ceramic board (2" thickness is great and the board is easily cut with a jig saw...or even a knife) on top of the tiles. If the ceramic board doesn't lay flat, you may use some damp sand (with a little clay mixed in) and a notched trowel to lay a thin leveling layer on top. This will allow you to set the cooking floor bricks, nice & level. These ovens can be VERY heavy, obviously depending on brick? cast? size? façade? etc., so I'd really want to make sure that existing outdoor concrete countertop was pretty beefy! We generally are looking at 4" hearth of reinforced concrete supported by concrete block (CMU) placed on a stable ground foundation slab of 4"-6" reinforced concrete.

There are many threads using this current layering convention/order for their ovens. Here's a link to one that has some nice pics of that base layering. (I used TinyURL to make this smaller link for you.)

https://tinyurl.com/yx9fhkoj

Hope that helps!