Curing and Insulating Questions

[Jim from Akron]

I finished my dome in the fall and will continue my build in the spring. I will insulate the dome, and then I plan to build a modular brick enclosure around the dome. I did 4 days of curing fires in the fall and then covered the dome with tarp for the winter. My first question is will I have to do the curing fires again in the spring before I insulate?

My second question is about protecting the blanket insulation: Can I just build the modular brick enclosure around and above the dome without finishing the dome with stucco. In other words, I'm thinking about leaving the blanket insulation exposed and then filling the enclosure with loose vermiculite insulation to add more insulation between the modular brick enclosure and the blanket-insulated dome. Is that a good approach, or should I stucco over the blanket and then add loose vermiculite between the stucco and the modular brick walls of the enclosure and above the dome?

I'm including a photo of my dome being cured and a photo of what the modular brick enclosure will look like.

[Jim from Akron]

Hi! I've been hoping for an answer to my 2 questions above. Can someone take a look and offer some advice? Thanks!

[SableSprings]

Jim, most ovens will have some moisture seep in over a winter. Even with a tarp cover, those bricks & the base insulation will take on some moisture. Hopefully you did a tile/weep hole layer to separate the concrete slab from the base insulation which helps give moisture another avenue of escape. It's always a good idea to do a couple low & slow firings after a long period of "storage" for any masonry oven to dry things out before building a cooking fire. Do a couple drying fires before putting on the insulation blanket.

As to your second question, when putting your blanket over the dome, you'll need something just to hold it in place without compressing it. Some tap screws around the base and wire over the batts should be more than adequate. Since you're planning a water tight/roofed enclosure, the addition of loose perlite or vermiculite certainly won't hurt at all. Do be aware that you can throw in some plastic bottles/jugs in the corners to reduce the amount of loose fill needed (it will take a lot more than you think ). Make sure your enclosure has some ventilation and is secure from critters who'd like to make that space a homestead. The loose fill will settle a bit over time, so being able to inspect or add more in the future if you think it's needed isn't a bad plan...

Hope that helps...enjoy the journey!

[Giovanni Rossi]

Hello Jim,

If you're protecting the insulation from rain with your planned structure, there's no need for stucco. If you have 3 or more inches of blanket, you may not dramatically increase the insulation value by adding the vermiculite. If you decide to go that route, some builders recommend blocking the corners of your enclosure with things like drywall scrap or even empty soda bottles to decrease the volume of vermiculite needed. I've also remember a recommendation to consider an access door to add more later as there may be some settling over time.

Just a technical note, your concrete products have cured long ago. You are doing only drying fires at this point. The usual recommendation is to have the dome insulation in place before the initial drying fires. This decreases the chance of cracks due to the differential in the temp of the inside and outside surfaces of the dome. If you did not do that last fall, it's probably still good advice for this round of drying, At this point you are driving out moisture that has accumulated over the winter. I perform this same process for my first fire in the spring. I don't do days of small fires as was done when the oven was first constructed.
I usually start in the morning with very small fires and maybe some lump or briquette charcoal if I have any. I gradually increase the heat with the intent of cooking dinner that evening. After that I'm good to go with a full fire pizza session the next time.

Good Luck.

[UtahBeehiver]

Plus one with both Mike and Giovanni's comments.