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nachtwacht 09-13-2013 02:44 AM

Is this plan (oven entry) structuraly strong enough ?
 
1 Attachment(s)
Hello,

I am trying to design my oven but am curious if the design I have in mind will be structuraly strong enough to withstand the forces that go with it.

The image shows the idea I have. The inside will be 19 inch wide (48cm) and 12 inch high (30cm). Full bricks will be used so it will be 8 inch deep (21cm)

It is going to be placed "in front of the oven". I want to make a heatbrake between the oven and this arch. The arch should also support the vent so the top bricks will be something like half bricks.

I have a few questions / options that I hope to find some answers for since I do like the design of this entry.....

1) will this be strong enough without any extra support on the side ? Some wool and stuco will be on the side but I doubt this gives a lot extra of structural strenght.

2) If I put vermicrete next to this structure (lets say 3 inch) wich will go round the oven, and then some stuco (another inch) will this give enough structural strenght ?

3) like 2, but now I will put some rebar in the vermicrete, wich goes all the way down into my concrete slab. I am reasonably sure this will give enough strenght... I just do not like to have to drill in the concrete so the rebar can go in there.

Thanks in advance for any help !

brickie in oz 09-13-2013 02:58 AM

Re: Is this plan (oven entry) structuraly strong enough ?
 
Quote:

Originally Posted by nachtwacht (Post 161728)

1) will this be strong enough without any extra support on the side ?

No..................

stonecutter 09-13-2013 03:36 AM

Re: Is this plan (oven entry) structuraly strong enough ?
 
You will either have to buttress or apply reinforced cladding.

nachtwacht 09-13-2013 04:34 AM

Re: Is this plan (oven entry) structuraly strong enough ?
 
Thanks both.

Any idea on how good vermecrite could / would work as reinforced cladding ?

Basicaly that is idea 2 and 3. Maybe I should add a 4th ?

4) use reinforced cladding out of fireproof concrete.

Will search here also for it. Had looked into buttress allready. I building a low down so have to use that there also (I want to use the rebar and vermicrete on that also) but had not searched for "reinforced cladding".

thanks so far for the help.

stonecutter 09-13-2013 04:40 AM

Re: Is this plan (oven entry) structuraly strong enough ?
 
Quote:

Originally Posted by nachtwacht (Post 161728)
Hello,

I am trying to design my oven but am curious if the design I have in mind will be structuraly strong enough to withstand the forces that go with it.

The image shows the idea I have. The inside will be 19 inch wide (48cm) and 12 inch high (30cm). Full bricks will be used so it will be 8 inch deep (21cm)

It is going to be placed "in front of the oven". I want to make a heatbrake between the oven and this arch. The arch should also support the vent so the top bricks will be something like half bricks.

I have a few questions / options that I hope to find some answers for since I do like the design of this entry.....

1) will this be strong enough without any extra support on the side ? Some wool and stuco will be on the side but I doubt this gives a lot extra of structural strenght.

2) If I put vermicrete next to this structure (lets say 3 inch) wich will go round the oven, and then some stuco (another inch) will this give enough structural strenght ?

3) like 2, but now I will put some rebar in the vermicrete, wich goes all the way down into my concrete slab. I am reasonably sure this will give enough strenght... I just do not like to have to drill in the concrete so the rebar can go in there.

Thanks in advance for any help !

http://www.amand.net/foto/entry_01.jpg

To be more specific...

q2 - It depends on how much weight your arch is going to carry. Full masonry chimney, then no, you should use reinforced cladding. If you are installing a SS flue, then yes, your idea will be enough.

q3- Reinforcement in V-crete ( or perlcrete) wont work well, be cause the insulation has weak binding properties.

Have you considered a different arch configuration?

stonecutter 09-13-2013 04:46 AM

Re: Is this plan (oven entry) structuraly strong enough ?
 
Quote:

Originally Posted by nachtwacht (Post 161736)
Thanks both.

Any idea on how good vermecrite could / would work as reinforced cladding ?

Basicaly that is idea 2 and 3. Maybe I should add a 4th ?

4) use reinforced cladding out of fireproof concrete.

Will search here also for it. Had looked into buttress allready. I building a low down so have to use that there also (I want to use the rebar and vermicrete on that also) but had not searched for "reinforced cladding".

thanks so far for the help.

I didn't document the process on my thread, but I applied 1" RC to my dome, which is a Neapolitan. Shortly after it was cured, I stood on top of it, just for haha's when I was framing the enclosure.

I do think a layer of v-crete or perlcrete would work, but I feeling it would have to be more than 3"...closer to 6". I will say that I have no data or past experience with this theory, just structural masonry intuition.

nachtwacht 09-13-2013 05:46 AM

Re: Is this plan (oven entry) structuraly strong enough ?
 
1 Attachment(s)
Quote:

Originally Posted by stonecutter (Post 161740)
I didn't document the process on my thread, but I applied 1" RC to my dome, which is a Neapolitan. Shortly after it was cured, I stood on top of it, just for haha's when I was framing the enclosure.

I do think a layer of v-crete or perlcrete would work, but I feeling it would have to be more than 3"...closer to 6". I will say that I have no data or past experience with this theory, just structural masonry intuition.

Intresting thread since it is almost the same as I have in mind to be building. What did you use there for cladding ? It is a thin layer. Does not look like you have put any rebar into it. I was thinking about using steel bracing myself around the oven like Tscarborough did wich he shows here here

Tscarborough still used concrete around it. I however wanted to use vermicrete since I did not want to add more mass to my oven. (I can live with 1 inch like you used though....)

Back to the entry arch... yes, I have considered other designs including those that are self supporting. It's just that I like this design better than the others. So if it will be to complicated / definatly not strong enough, I can do something else.

since a picture usualy says more than a thousand words, this is basicaly what I had in mind for option 3) It is a top view and the vermicrete goes all the way round the oven to the other entry arch.

And yes, it will be a SS double walled pipe so that will not be to heavy....

stonecutter 09-13-2013 06:00 AM

Re: Is this plan (oven entry) structuraly strong enough ?
 
Quote:

Originally Posted by nachtwacht (Post 161741)
Intresting thread since it is almost the same as I have in mind to be building. What did you use there for cladding ? It is a thin layer. Does not look like you have put any rebar into it. I was thinking about using steel bracing myself around the oven like Tscarborough did wich he shows here here

Tscarborough still used concrete around it. I however wanted to use vermicrete since I did not want to add more mass to my oven. (I can live with 1 inch like you used though....)

I used wire fencing as reinforcement...one layer wrapping the soldiers horizontally, then another that covered the dome, extending over the soldiers. The cladding layer was around 1" thick, with sand being the only aggregate.

As mentioned, rebar wont do anything in Vcrete. You could try a couple layers of wire mesh, but I still think the tension will brake up the insulation. But it will be encased with stucco too, so this may be over thinking a bit.

stonecutter 09-13-2013 06:15 AM

Re: Is this plan (oven entry) structuraly strong enough ?
 
1 Attachment(s)
Quote:

Originally Posted by nachtwacht (Post 161741)
Back to the entry arch... yes, I have considered other designs including those that are self supporting. It's just that I like this design better than the others. So if it will be to complicated / definatly not strong enough, I can do something else.

since a picture usualy says more than a thousand words, this is basicaly what I had in mind for option 3) It is a top view and the vermicrete goes all the way round the oven to the other entry arch.

And yes, it will be a SS double walled pipe so that will not be to heavy....

I built an oven arch like that on my other personal WFO. Besides this one and a pre-cast, all the other ovens I have built, including restoration of historical beehive ovens, have had semi circular or equilateral arches.

The solution I came up with for my CT home oven was to set back the sides of my oven opening. Compression from the dome acted like a buttress on the sides of the arch, so the lateral pressure from the walls of my opening were contained. I used no cladding on that oven....I parged the outside of the dome and it was surrounded by insulation batts and loose vermiculite.

Here is a picture of the opening....
Attachment 38861

You lose a bit of space doing it that way, but I didn't find it to be a negative at all, because you don't usually cook within the first few inches of the opening anyway. I just didn't want the extra work of building a buttress or have to encapsulate the arch with reinforcement. The only reason I used reinforced cladding on my current oven is because it is a low dome (Neo) with soldiers.

Further, my arch carried 3 full lengths of 8"x8" clay flue and a small fire brick 'smoke shelve'.

nachtwacht 09-13-2013 06:20 AM

Re: Is this plan (oven entry) structuraly strong enough ?
 
Quote:

Originally Posted by stonecutter (Post 161743)
As mentioned, rebar wont do anything in Vcrete. You could try a couple layers of wire mesh, but I still think the tension will brake up the insulation. But it will be encased with stucco too, so this may be over thinking a bit.

ok. You confirmed one of my other things I feared. Vermicrete is probably not good under compression. The rebar will make the vermicrete crack over time and then the rebar is useless, both around the dome and next to the entry arch.

So it has to be either a steel wire wich is put tightly against the stones or wire mech (as in chicken wire right ?) and 1 inch of concrete around the dome.

However, since the entry arch will be showing about half (the other half will be in the stucco / insulation) I have to come up with a good way of reinforcing that...

Anyone ever tried to drill a hole in the concrete slab, put rebar in there, and then also drill a hole in the first 4 stones in my picture ? I don't see them falling then anymore and I would that it is a fairly easy solution. Since I plan to incorportate a thermal break the entry arch should not get to hot and no heat should go into the concrete slab....

I should probably file the above as "Option 5" :)


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