NW Ohio Build - Opinions welcome

[david s]

Re: NW Ohio Build - Opinions welcome

There are two schools of thought re curing with insulation on or off and pros and cons for each. I prefer to do it with the insulation in place. There are certainly more stresses on the structure when it is first fired because the temperature differences are greater when the lower parts of the oven are moister and therefore cooler. I would think this would also be the case if you fire it up without the steel bracing.

[perrysburg]

Re: NW Ohio Build - Opinions welcome

I plan on framing out the oven with steel 2x4's and wrapping with cement board to stucco to match the bottom. I'm thinking if done right (and with a few cross beams where the top row/ 45 degree cut bricks support the arches) the framing will not only provide a structure for the cement board but also support the arches. The only unkown is the ceremic blankets--not sure how tight I can get the crossbeams with a layer of ceremic between the bricks and 2x4's.

I was planning on curing with small fires while the wooden 2x4's shown in the picture are in place and once that had completed removing and starting to build the steel framing. Should I (or can I) fire cure the oven before framing out with steel 2x4's or will the curing process weaken the bonds immediately and put the structure at risk?

ps., The refractory mortar recipe I used is 3 parts block glass mortar / 1 part fire clay.

[david s]

Re: NW Ohio Build - Opinions welcome

Because your vault is not laid on bond, it's radius is quite large and your end wall is outside rather than under the vault, you should consider steel bracing right around the oven where the vault meets the walls.

[NCMan]

Re: NW Ohio Build - Opinions welcome

I think you want to stagger the lengths of the dome bricks so you lay them on bond.

Ordinarily, that would be true and make it stronger. However, that's not how most of those ovens are built. It will be fine.

[GianniFocaccia]

Re: NW Ohio Build - Opinions welcome

I think you want to stagger the lengths of the dome bricks so you lay them on bond.

[perrysburg]

Re: NW Ohio Build - Opinions welcome

Started the arches yesterday....used a cement bag which is analogous to what a pastry chef would use for decorating a cake.

[perrysburg]

Re: NW Ohio Build - Opinions welcome

it is cement board. I saw it used in another thread. It made sense to me that it would more evenly disperse the weight of the firebricks on top of the foamglass. The foamglass is brittle and the cement board protects the foamglass from damage while lying the brick--hope that makes sense. -A

[gugahulk]

Re: NW Ohio Build - Opinions welcome

No plans to buttress per se, however I plan on insulating with ceremic blanket and then some sort of Vermiculite/Perlite mortar mix which should help to strengthen the walls. Until I get that figured out I will create a wood frame to support the walls as I build the arches. Remember I'm winging this so I'm prob not the best example of how to...

What is that board you put between the insulation board and oven floor? Why was that put there? I am very curious... and What is it? Looks like cement board.

[NCMan]

Re: NW Ohio Build - Opinions welcome

No plans to buttress per se, however I plan on insulating with ceremic blanket and then some sort of Vermiculite/Perlite mortar mix which should help to strengthen the walls.

I don't personally have any hands on experience w/that type of oven. However, I don't really think adding a layer of Vermicrete/Perlcrete will do much to add any real strength to the exterior of your oven, especially over the top of the blanket. I wouldn't plan on it for that purpose. It will add insulating value, but should not be counted on to add any real structural strength to the oven. My 2?.

[david s]

Re: NW Ohio Build - Opinions welcome

You also need to consider the radius of the vault. A flattish arch exerts way more sideways thrust on to the top of the walls than say a semicircular one.

[Greenman]

Re: NW Ohio Build - Opinions welcome

The decision about if you need to buttress your arch structures is a critical one. I don't think that luck has much to do with it and if you get it wrong the failure could be catastrophic!

The basic principles can be found here Auroville Earth Institute and armed with this information the decision can then be informed rather than a gamble.

Good luck with it.

[gugahulk]

Re: NW Ohio Build - Opinions welcome

No plans to buttress per se, however I plan on insulating with ceremic blanket and then some sort of Vermiculite/Perlite mortar mix which should help to strengthen the walls. Until I get that figured out I will create a wood frame to support the walls as I build the arches. Remember I'm winging this so I'm prob not the best example of how to...

Looking good. I have very similar plan like you. However, I will be using 5 ceramic blankets and wrapping it with stocco to finalize it. I will not do any percrete. I hope it stays and does not crash down... I have alot of money tide into it. Just like all of us... Will you be doing the end walls inside the dome of outside the dome? I am doing it inside for extra streght but I must tell you, it is a B!&CH to do. So must work. Last night took me all night 3 hours just to lay 5 bricks. I finish the front and plan to do the back tonight. I will post pictures tonight.

[perrysburg]

Re: NW Ohio Build - Opinions welcome

No plans to buttress per se, however I plan on insulating with ceremic blanket and then some sort of Vermiculite/Perlite mortar mix which should help to strengthen the walls. Until I get that figured out I will create a wood frame to support the walls as I build the arches. Remember I'm winging this so I'm prob not the best example of how to...

[gugahulk]

Re: NW Ohio Build - Opinions welcome

Updated photos.

Very nice, you are more or less at the same stage as me. Are you planning on buttressing the sides of your oven in any way? If so let me know your plan. I am troubled but buttressing.

[perrysburg]

Re: NW Ohio Build - Opinions welcome

Updated photos.