36" Pompeii Build, West Lafayette, IN

[Cubslover]

Re: 36" Pompeii Build, West Lafayette, IN

Gulf is right, no way to anchor to the insulating layer if it is vermiculite or perelite. But it is a lot easier to pour.

The limestone should work fine, it will stain because it is really a big sponge. Also be careful handling it, those long slabs are like glass, they can snap in a heartbeat.

Good to know. I may have to cut it down a smidge and clean it up.

So the plan now is to frame up a 50x50 form for the insulating layer. It should cover the 36+9 for the width of the oven and the 36+10.5 (6" vent landing + 4.5" brick) for the depth.

Now, I still have a question about what to do with the hearth layer. It's 4", but not completely level (since I planned on bringing the entire hearth level up with insulating concrete, before realizing I can't anchor to it). The form that is still in place IS level.


My options as I see it are:
1. Frame up the insulating form, pour the outside with regular concrete and bring it to level, then remove the form and pour the insulating layer to level inside the new - 2nd layer of concrete? I'm afraid that, if I pour another layer and anchor the wall studs to it, they won't be sufficient to hold the walls in place. This new layer of concrete will be 3.5" thick x 6.5" wide on the sides and 14.5" wide on the front/back.
- If this is all poured in one with some rebar, will it hold the steel studs/hardibacker/stone veneer? I can't see much leveraging force pulling the walls out and down, as the weight should be dispersed DOWN into the slab.

2. Leave as planned, form up and pour the insulating layer (will be completely level), leaving the hearth slightly unlevel. I will have to put some extra work into the metal studs to make sure the roof line is level when the walls go up.

Pictures below to help explain. I'm probably putting more thought and worry into this than necessary.

[Cubslover]

Re: 36" Pompeii Build, West Lafayette, IN

Thank you again. It helps immensely. I haven't been sure what to expect.

[Gulf]

Re: 36" Pompeii Build, West Lafayette, IN

Perfect, thank you sir. Always timely with good advice. I believe I will pour a rectangle over-sized to my oven to assure it's covered and because it's easier to frame than that^^^^!!!

nice job

That will work just fine. That is what I was going to do. But, I changed my mind and went for an Igloo, instead of an enclosure. If you haven't read it on any of the other threads already, leave your vcrete forms in place for as long as you can. The corners will chip easily if it they are not protected. (That will protect it from alot of abuse during the build of the dome.) You will, think that the vcrete doesn't have enough portland in it. But, do stick to the formula. You will at first think think that there is no way that this stuff will ever hold up an oven. It will, trust me, "The Queen" is a little on the portly side. No problems . If you want a smooth, rigid cement type finish to your vcrete, do a little extra screeding and floating to the surface. Working the surface brings a little portland to the surface and makes smaller particles out of the vermiculite. That will only effect the surface of your insualtion layer, and not the overall R-factor. But, it will make it a little easier to build on. David S. is the first one that I read about doing this. I discovered it by accident. I did the Pie-R-Square and "just knew" that I had enough vermiculite on hand. As it turned out vermiculite shrinks just a little from dry volume to poured volume. You can not count the portland toward the final volume. On the day of the pour, a Saturday (the nursery closed at noon) I ended up not having enough vermiculte for the pour. With about 3/8ths" to 1/2" left to pour to the top of my forms, I ran down to Walley World and bought enough fine horticulture grade to finish. It doesn't take many of the small, pretty colored, bags from the big box stores to pay for a big a bag of bulk vermiculite .

I hope this helps.

[dakzaag]

Re: 36" Pompeii Build, West Lafayette, IN

Gulf is right, no way to anchor to the insulating layer if it is vermiculite or perelite. But it is a lot easier to pour.

The limestone should work fine, it will stain because it is really a big sponge. Also be careful handling it, those long slabs are like glass, they can snap in a heartbeat.

[Cubslover]

Re: 36" Pompeii Build, West Lafayette, IN

Perfect, thank you sir. Always timely with good advice. I believe I will pour a rectangle over-sized to my oven to assure it's covered and because it's easier to frame than that^^^^!!!

nice job

[Gulf]

Re: 36" Pompeii Build, West Lafayette, IN

Here is my answer.



Pour the vcrete layer just a little larger than the foot print of your oven.

PS: Include a moisture barrier between the structural hearth and the vcrete layer .

[Cubslover]

Re: 36" Pompeii Build, West Lafayette, IN

Ok folks, the next portion of this build has me a bit confused (or rather un-learned).

The hearth is down, but when I poured it I planned on pouring the entire next layer with perlicrete and leveling it to the form. I floated and did my best to check the level on this hearth pad when it was wet. Now that I think about it, I don't know if the metal studs will anchor solidly enough to the insulating concrete. What says you? Can I anchor the studs to the insulating layer if I do pour the entire layer?

My other option is to build up a form to cover the footprint of my oven and landing and just pour that with the insulating concrete. After it cures, I'll have to then pour more concrete to level off the outside so I can solidly anchor the metal studs. That is, IF the hearth is unlevel.


As a side note, a friend of mine has a limestone mantle he tore down from his house. I need to take a look, but that may make a very cool counter-top.

[Gulf]

Re: 36" Pompeii Build, West Lafayette, IN

What they said.............X2 .

[dakzaag]

Re: 36" Pompeii Build, West Lafayette, IN

Sheza keeper!

[texman]

Re: 36" Pompeii Build, West Lafayette, IN

you are deserving of your favorite beverage.

Looks good and it gets better.

Texman

[Cubslover]

Re: 36" Pompeii Build, West Lafayette, IN

Thanks both! I poured the hearth today. Totally sucked, 20 bags, wheelbarrow method, shoveled it all up to the hearth.

Wife helped float it.

[dakzaag]

Re: 36" Pompeii Build, West Lafayette, IN

It is probably easier to do two separate pours, unless you just leave your form material in place. Still probably easier to do separately just because you're not worried about messing up on pour while working on the other.

I use both, but I am a little more careful when working for a customer. Proven materials only for an oven for sale, I experiment on my family and close friends.

That sounds a lot worse than it really is, but I think you know what I mean.

The recipe from FB is a good mix, it has proven itself for years.

[texman]

Re: 36" Pompeii Build, West Lafayette, IN

yes two pours are fine and probably better, imo. Home-brew is very proven around here. I used the high $ mortar and i don't think i have any advantage other than less money to keep up with.

Texman

[Cubslover]

Re: 36" Pompeii Build, West Lafayette, IN

Ah. You wanted me to be the Guinea pig? I see I assume you used the Homebrew?

On another note; Can I pour the hearth and the insulating layer on different days? I can't see a reason why not, but the guide shows it going down at the same time.

[dakzaag]

Re: 36" Pompeii Build, West Lafayette, IN

It will work, I use something different, but only because I stock it for restoration work. For the purpose of an oven that will do fine.
I was hoping you would get enamored by the refractory mortar they carry in there. I have no idea what it is, but at $50 per bag, I am going to let someone else experiment and learn the hard way.