Oregon 42" Pompeii Oven

[Corsairmo]

Hello all, long time lurker, first time poster. I've been looking at building a pizza oven for years, and the time is finally here. I figured I could catch you all up on what I've done so far. I decided to build a 42" Pompeii oven on a corner installation. The stand is cinder blocks with three monolithic arches, which almost turned out perfectly. Keen eyes will spot that I failed to properly reinforce one the right-most arch so its a bit crooked. Otherwise success thus far!

[edonovan]

Looks like quite the set up! Very Nice work.

[Corsairmo]

From there I put together the countertop. This was my first time hand mixing in concrete colorant, and I think it turned out well for a nice chocolate brown.

[Corsairmo]

Looks like quite the set up! Very Nice work.

Thanks edonovan, I'm very excited about it. I have have some college experience with pouring concrete for a few years, but the brick working is all new to me, so I have been trawling here and elsewhere to hopefully avoid mistakes! I'm really inspired by UtahBeehiver build! his pictures and descriptions have been invaluable!

[Corsairmo]

I had a hard time finding a good insulation source, but was able to get a hold of some FoamGlas in the end, which I'm quite happy with. Next step is positioning and centering the oven on the table. I haven't really worked through all the considerations for the archway, vent space, depth etc, so now I see myself needing to move the oven back further than I thought initially. Hoping to work on it during my Thanksgiving staycation break.

[UtahBeehiver]

Good start, what part of Oregon? You have a great resource and one of our moderators (SableSprings aka Mike) located in Roseburg. PS, thanks for looking at my build portfolio, but there have been many improvements and innovations since I finished the oven in 2012 so be sure to incorporate these in your build, too many to list so you will just have to ask the forum.

[Corsairmo]

Hey thanks for looking in Russel! I am in Astoria out on the coast, so a fair drive from Mike, but I will always welcome feedback from those who have gone ahead! I will do my best to poke around to find out the latest and greatest.

[Chach]

Hi looking good so far. Good pickup on the foamglas. Did you sourced some calsil board to out on top of the foamglas? Can't really tell but it seems you are using 1" foamglas so far that is rated for a service temp of 806 F . If you are not putting calsil board on top of the foamglas I would highly recommend it. Foamglas is good for a bottom layer on top of the structural slab as its moisture resistant but you will need something on top of that. Thermo 12 gold is rated up to 1200 F and the basic plans recommends 2" of this type of insulation if you are using calsil instead of vermicrete. I used 2" of foamglas and 2" of thermo 12 gold and I'm very happy with the results. Looking forward to seeing your progress.

Ricky

[Corsairmo]

Hi Ricky,
Thanks for the information, I have seen several people who used the CalSil board on top of the FoamGlas but I thought that was because of the fear of crushing or breaking it... I don't have access to CalSil board at this time, so I was going for a leveling layer of fireclay then the brick floor on top... My FoamGlas is 2" thick, so I think I'm OK insulation-wise, but what exactly does using FoamGlas outside its service range imply? I am assuming I wouldn't be melting it...

[Corsairmo]

I've been looking at it for a bit and all I can find is that its listed limits are "The melting temperature of FOAMGLAS® insulating slabs is above 1000 °C (DIN 4102-17) and the maximum application limit temperature is approx. 430 °C." However in another publication it's melting point is listed as "1350F." So while there may be some sort of degradation above about 800F, I can't seem to find anything that would make me think I am in danger of failure. However, a) I am the absolute opposite of any sort of material engineer, so much wiser minds please feel free to teach me, and b) many people here have built ovens while I have built exactly zero thus far.... so again, I wish to learn!

References for the temps listed above:

https://www.foamglas.com/-/media/pro...n.pdf?la=en-gb
http://www.ais-group.com.au/images/p...14_Annex-A.pdf

[SableSprings]

If you are concerned about the Foamglas melting of degrading, just use a thin layer (1" or so) of 5 :1 perlite/cement on top as a leveling layer for your cooking floor. Generally when you're firing and using the oven, the lower portion of the floor bricks won't attain the temps of the top side. Using a thin layer of insulating perlcrete (or vermicrete) will give you plenty of "protection" for the Foamglas.

Looking forward to your build and always great to have a fellow Oregonian in the forum. It's been a while since I've been North of Newport, but I may wander up your way this next summer.

[CapePizza]

I'll throw in my 2¢. I had used 1.5 inches of foamglas under the 2 inch CaSi board as the Foamglas is hydrophobic. Any water that were to seep under the base would not work its way up to the CaSi board.... that's the theory at least.

Actually, just looked at my receipt from the Foamglas supplier... it was 2 inch thick I had used.

[Corsairmo]

Thanks for the feedback everyone, the forums are a great source of wisdom and experience! I just picked up a bag of perlite to make a 1" topping layer above the FoamGlas, better safe than sorry! I hope to spend most of today working on it, pictures to follow!

Mike, you'd be most welcome up in Astoria once the oven is done! I don't know of anyone in the area who has ever made an oven. Any advice for making an oven in such a rainy place? I used to live down in Medford and Newberg and would pass through Roseburg all the time. Now, with living on the coast travel is a bit more scarce, but we do have family down in Medford, once this pandemic is over maybe I'll plan some time to stop in Roseburg!

[SableSprings]

Thanks for the Astoria welcome Corsairmo! There are a couple folks in the state with WFOs and several in Washington. My advice on the oven is to put a cover over the oven and a space for outside party seating/eating. There are lots of schemes & waterproofing additives to keep the insulation dry in rainy or humid climes, but the bottom line is water ALWAYS will win. If a simple carport structure would be an option, I'd highly recommend it. The only things you have to be aware of with a installed roof are 1) "hitting" the space between joists with your oven flue pipe & 2) making sure you have a solid roofing flange plan for the chimney...so you don't get leaks down the stove pipe... Do think about your wood loading path & main wood storage area. As you can see in my build, I used a cart system for wood and party supplies built into the base and built a wood shed nearby and somewhat out of sight for the couple cords of wood I keep on hand.

With the mild temps of the coast, I don't see any problems continuing your build through the fall and most of the winter. The assumption there is that you would get one of those 10' x 10' portable tent covers to put over the oven. Not only to keep your oven area dry, but you as well while laying bricks...

You would be most welcome to stop in Roseburg anytime I'm not traveling. If I had a couple days notice, I could make sure you had a loaf or two of bread to take down to the family and a slice or two of pizza to help fuel the last couple hours to Medford...

[Corsairmo]

Well, I think I succeeded in laying out the 5:1 perelite cement mix. The perelite I purchased seemed pretty coarse, with chunks as big as pea gravel, so I'm a little worried about how well it will bond. I mixed in a bit of sand which seemed to help draw it all together...