Starting my barrel vault

[stonecutter]

Re: Starting my barrel vault

Thermal expansion and joint failure weaken an ovens structural integrity..

Yeah, which is what makes a flying buttress in this application even more funny to me.

[Tscarborough]

Re: Starting my barrel vault

Yeah, no need to go all gothic cathedral. Since construction is where it is, the next best solution is to use the exterior finish as the buttress.

[gugahulk]

Re: Starting my barrel vault

Yeah, no need to go all gothic cathedral. Since construction is where it is, the next best solution is to use the exterior finish as the buttress.

The finish will be just stocco. It will not be strong enough. So you think 2" of perlcrete will do the job for me? Or msybe 2" of refractory mortar would be even better since i must increase the mass on the side walls any ways. Let me know what you think. Ur idea of interlocking on the first couse would have been perfect. But too late for that. See where i am at in pic below

[david s]

Re: Starting my barrel vault

Even a thick heavily reinforced outer stucco shell will not be of much benefit to supporting your side walls if you have 5" of compressible ceramic blanket between the oven walls and the outer shell.

[Tscarborough]

Re: Starting my barrel vault

Stucco monocoque is fine, but as noted, not with blanket. That is how the Italians build their ovens, with a stucco shell to reinforce the low dome.

[stonecutter]

Re: Starting my barrel vault

In tandem with the leca/Portland insulation.

[gugahulk]

Re: Starting my barrel vault

Ok guys here is my plan and I have 2 options but not sure which one I should go with.

1st I will be adding no more than 2 inches on the side walls of the oven of buttress. Now these side walls will be either

perlcrete with a ratio of 5 to 1 or

100% heat stop refractory mortar.

My perlcrete I am planing on using heat stop refractory mortar also instead of portland cement. So, which one do you like better?

2nd Once that part is complete, I will wrap up the vault with 5 ceramic blankets and finish with a thin layer of stocco as its just for finish and not for support.

Let me know the best option for me. Look forward to your replies.

[NCMan]

Re: Starting my barrel vault

I think you are talking about a cladding, right? HeatStop is not designed for that use or thickness, not to mention the co$t. Better to use Portland and sand mixture, as has been mentioned already. Neither one of the choices you mentioned are a good choice for a cladding to strengthen. Also, one will add lots of mass and one won't. You are comparing apples to oranges, my fellow WFO'er, if I understand you correctly. My 2?.

[gugahulk]

Re: Starting my barrel vault

I think you are talking about a cladding, right? HeatStop is not designed for that use or thickness, not to mention the co$t. Better to use Portland and sand mixture, as has been mentioned already. Neither one of the choices you mentioned are a good choice for a cladding to strengthen. Also, one will add lots of mass and one won't. You are comparing apples to oranges, my fellow WFO'er, if I understand you correctly. My 2?.

So McMan your suggesting would be ad 2 inches of perlcreate with a mix of 5 perlite 1 portland cement and 1 sand?

[NCMan]

Re: Starting my barrel vault

So McMan your suggesting would be ad 2 inches of perlcreate with a mix of 5 perlite 1 portland cement and 1 sand?

No, I wasn't suggesting either one. For starters, Perlcrete is typically just Perlite and Portland. Usually, no sand. Perlcrete is used primarily for insulation purposes. Portland and sand mixed together will add strength, but will also add mass, which you said you did not want, w/your firewood situation. I would give some serious thought to starting over and following Tscar's (and others)advice. Really. You've got yourself in a spot right now, w/few, if any, "best practice" options. I would probably clad it w/Portland and sand, but then again, I have virtually unlimited firewood resources and wouldn't mind the extra mass.

[gugahulk]

Re: Starting my barrel vault

No, I wasn't suggesting either one. For starters, Perlcrete is typically just Perlite and Portland. Usually, no sand. Perlcrete is used primarily for insulation purposes. Portland and sand mixed together will add strength, but will also add mass, which you said you did not want, w/your firewood situation. I would give some serious thought to starting over and following Tscar's (and others)advice. Really. You've got yourself in a spot right now, w/few, if any, "best practice" options. I would probably clad it w/Portland and sand, but then again, I have virtually unlimited firewood resources and wouldn't mind the extra mass.

I agree with you 100% that Tscar's was a perfect solution for me. But I dont want to start over. I really dont want to add the extra mass. Do you think by adding an addtional 2 inches of portland and sand mix will do the trick? If so what mix do you recommend? 1 portland and 2 sand?

[Tscarborough]

Re: Starting my barrel vault

I think if I was in your situation, what I would do is drill 3 holes evenly spaced down the wall, tight to it, and then epoxy rebar uprights. Since it will be almost impossible to get them as tight as possible, plan on using wedges cut from firebrick to keep the bars in tension (Wedges at the top of the rebar, of course)

[gugahulk]

Re: Starting my barrel vault

I think if I was in your situation, what I would do is drill 3 holes evenly spaced down the wall, tight to it, and then epoxy rebar uprights. Since it will be almost impossible to get them as tight as possible, plan on using wedges cut from firebrick to keep the bars in tension (Wedges at the top of the rebar, of course)

how about ad another course to the side walls? But instead of doing a whole brick I would do it as 1/2 brick. I would split every brick in half and make another wall. I really did not want to ad any more mass but looks like I will have no choice. If I did that would that work? Would that be stronger than portland cement?

[david s]

Re: Starting my barrel vault

Just how far have you got? If you have not built the vault yet you may want to consider removing some wall bricks so they are only two courses high then building a semicircular vault instead of a large radius one. Better still remove all the bricks and build a dome.

[gugahulk]

Re: Starting my barrel vault

Just how far have you got? If you have not built the vault yet you may want to consider removing some wall bricks so they are only two courses high then building a semicircular vault instead of a large radius one. Better still remove all the bricks and build a dome.

I am up 4 courses. I don't really want to start over. I know you guys are masters and will come up with a perfect solution to my issue. I really need the help here.