May 25, 2011 - 12:54pm
Earth oven collapse
Well this sucks. After many days (and a few dollars) I finished my earth oven last friday. Two layers (thermal and insulation with straw mix). I didn't have time to cover it and it rained heavily today completely collapsing both layers of the top of the dome.
I had to buy fireclay and I don't want to have to do that again so reuse is crucial. . Anyone have ideas for rebuilding without refilling it with sand (which would basically be impossible, plus my sand is now gone that I used the first time)? I don't want to tear it all down because I think I'll lose too much clay and end up with straw mixed throughout.
If I have to tear it all down I may just rebuild with firebrick instead of earth.
Any help or sympathy?
sympathy, but no help I'm afraid.
So sorry to hear that your efforts came to not much.
Oh man, that's awful. I am so sorry. I like the firebrick idea though. When I was a child and lived with my grandparents in rural area, my grandparents rebuilt their earth oven every 4-5 years. I don't know why, maybe the ground was shifting slightly underneath with time, but I remember doing it, helping and it wasn't a big deal, not really.
wishing you the best. Don't give up.
So now while it's wet... scrape it all into a pile and mix well, don't worry too much about the straw, might even be an improvement! Whatever is on the inside will burn out with the first fire. The rest becomes insulation. Might have to add a little to the outside layer. Let it dry extra slow.
A cubic yard of sand can't be that expensive. You will manage and make it even better!
out of the clay pile? Pre-molding the bricks and letting them dry separately, you get faster drying power with the whole oven when it's back together. Sort of both ideas combined. ??? With a few pieces of wood, make a frame, press and scrape the "super mud" into it and push out. I don't know if I would let the bricks dry completely but much of the drying shrinkage would be reduced (in the final oven) and you can pre-form keystone blocks as desired. :)
Thanks for all your encouragement/sympathy everyone. I was determined not to give up so I've started over. Step #1?? A roof!!
So this past weekend I built a roof over the oven to prevent rain issues in the future, hopefully this will increase my success rate the second time. I also think I probably used too much/to large pieces of straw for my insulation layer. When I tried to move the collapse the straw was HEAVY with water...I think that may have been the source of my problem. So I plan to remove the straw from the mud as much as possible (With a pitchfork, I think) and really grind it up using my mower, so I have much smaller pieces next time. I'd love to use sawdust instead, but I dont think I can find enough.
Anyway, round 2 begins :)
That really is too bad about your oven disaster. I have been looking at possibly building one of those ovens. The idea of baking bread or anything for that matter in one just seems like such a wonderful idea.
I hope your second round proves perfectly successful. You mentioned that you want to chop up your straw. I wouldn't chop it too much because don't you need the long strands to give your cob its strength. Sort of like adding rebar to cement.
Well, no one can call me a quitter :)
I've now completed my second complete rebuild of the oven and it's better than it was the first time! Step 1 this time was to build a roof :) Once I did that I felt much more confident that it would hold up during heavy rain.
I ended up having to sift ALL my mud through a wire screen to get the straw out and, while that was alot of work, I think it helped mix my mud even more, so that's good.
The only thing I'm not real confident about is that my second 'insulation' layer actually had very little straw in it. It was almost just a second thermal layer with maybe a tad of straw...I'm hoping this does the job.
My problem before, I think, was that without the straw being really chopped up it got HEAVY when it got wet. Chopping it is absolutely necessary. The problem is I didn't have the means (or frankly the energy) to chop it all and try to mix it with my second layer...so we'll see. I'm hoping it'll hold heat.
Regardless, the end of the story (so far) is happy. Oven is complete and drying as we speak. I'll probably pull the sand out next weekend...(that's another thing I changed, letting the whole thing dry before pulling the sand out!)
Bravo. Looking forward to seeing pictures when it dries out and you fire it up.
That sounds great Bob. It really sounds like you got it all figured out. I can really see having a roof over your head would be alot more comfortable to use the oven in foul weather. Hey, you went to a lot of work and didn't give up, good for you. That is beyond excellent. I can see leaving the sand inside to allow the oven to dry for a while being a brilliant idea. Let us know how it goes and if you can include some photos. Especially some photos of that amazing bread that you will be baking in your new oven. Excellent work.
I also decided to name my oven....I dubbed it "The Little Red Hen" :) If you know the children's story it's totally the story of my oven and it's future: I spend days (weeks?) killing myself over it without a single offer of help from friends or family. But, I'll predict they won't have a problem helping me EAT what comes out of it :)
I even scratched a (pretty sad) chicken outline across it's arch. :) Pics below...
THE BIG HOLE! (and I thought this would be the hardest part...ha!)
Built a firepit for grilling right next to it!
(note that the first 3 pics have a slightly different layout...they were from the first version before the collapse. Afterwords I changed the brick floor configuration a little)
Nice. That looks great.
I have half a shelf's worth of books on earth oven building, yet I've resisted taking the plunge due to moisture issues. I'm afraid any earth oven I build will simply wash away! (Life in the subtropics means year-round rain.) Your re-build looks great. I have decided to save my pennies for a refractory concrete modular oven.
enough and the oven insulated enough that it won't catch fire! It looks a tad low to me, of course its my eye, but will hope it works out for you.
The oven is nice, I'm just waiting for some stuff to move off the lot so I can build one on the level, my back yard where it would be the best spot, is definitely not level. Not to mention where the level spots are its covered with trees. A pain to be sure.
looking at your photos, it appears that your wooden roof is vulnerable to flames coming out of the front of your oven. As time goes by, the wood will become more likely to ignite. There are ways to protect a wood overhang from flames. Stu
I'd swap out the wood for tin, personally. Great oven, though. But yeah, that is going to catch on fire.
I really like the way your earth oven looks. They have an earth oven at Forts Folle Avoine in Wisconsin with a similar shape.
I believe they used sort of woven branch dome for shaping it. It has a crack or two in it, but still worked fine last I saw it.
Have you fired yours yet?