Work of Love and Passion... Miami FL

[mrchipster]

Re: Work of Love and Passion... Miami FL

First of all thanks for this! Grateful for this knowledge, question why whould I put a vapor barrier of cardboard under the slab? than the slab it self will not be attached the the bricks. Did I understand this correctly? There should be no heat at all there.

And the first layer of bricks on the dome and floor of the oven will not have any motar at all? I understand replacing the bricks on the floor of the oven but how would I ever replace the side? unless there is another reason for it doesn't make sense to a novice like me. Sorry for the question... and thank...

We have a disconnect going on here. I need to ask you a couple of questions.

Are you building your dome on top of your floor? or are you building your floor inside the dome and cutting the floor into a round shape?

[gugahulk]

Re: Work of Love and Passion... Miami FL

We have a disconnect going on here. I need to ask you a couple of questions.

Are you building your dome on top of your floor? or are you building your floor inside the dome and cutting the floor into a round shape?

I was planning on building the floor inside of the side walls. Which way do you recommend?

[mrchipster]

Re: Work of Love and Passion... Miami FL

Just sent you a PM. Call me.

[DavidApp]

Re: Work of Love and Passion... Miami FL

Did you leave the door in place for the whole test of the charting?
Was the wind and outside temp about the same for the duration of the test?

Hello Chip
The door was in place all the time except for loading the oven or checking the temperature.
The oven is in the breezeway so it is not effected by wind that much and the ambient temperature was in the high 60s to low 80s.

I was comparing the results of the 2" door to the 4" door. I am noticing that the temperature profile changed depending on how long I fire the oven.

David

[BuilderMakerCreator]

Re: Work of Love and Passion... Miami FL

Hello,

Another super low cost insulation available to you is to use Perlite (2 cu-ft bag from Home Depot or Lowes for $16 or a 4 cu-ft bag for $10 at Atlantic FEC in Homestead, Fl). You could use sodium silcate as a high temp binder or any other high temp adhesive/aggregate, or simply use it loose to fill the gaps. It will add NO STRENGTH to the structure, but it does provide very good insulation. I've seen it used as a loose fill between two structural domes (one inner, one outer) which helped with thermal expansion as well. The outer dome didn't even melt the snow atop it when the owner fired up his oven. The better part of perlite as an insulation is its lightweight. A 2 cu-ft bag weighs approx. six pounds.

Perlite will reduce the heat within the oven from passing through the walls where you place it. It WILL NOT act as a temp holding medium/mass like clay, stone, marble, iron, etc. Something has to absorb all of that heat so it can in turn radiate back into the oven space when the fire has expired. In other words, if you replace too much of the inner heat absorbing mass of your oven with heat resistant mass (insulation) your oven will heat up faster during firing, and cool faster when the heat source dies out. You won't have that nice heat soaked oven effect we all seek.

[gugahulk]

Re: Work of Love and Passion... Miami FL

Base getting ready for concrete. Please any advice would be great. See the pictures below and if I am doing anything wrong now is the time... :-) Look forward to any comments.

[gugahulk]

Re: Work of Love and Passion... Miami FL

Hello,

Another super low cost insulation available to you is to use Perlite (2 cu-ft bag from Home Depot or Lowes for $16 or a 4 cu-ft bag for $10 at Atlantic FEC in Homestead, Fl).

Thanks for this, I will looking to it. My goal so far is 4 to 5 ceramic blankets and 4 inches on the floor. Maybe 2 more inches on the dome of perlcrete. What do you think? Also 4 inches on dome as mass and 2.25 inches on the floor.

[DavidApp]

Re: Work of Love and Passion... Miami FL

Hello

You need plenty of support under the forms and for the sides of the forms as well. Wet concrete is heavy and you do not want a blowout. Also make sure you can get the forms out after the concrete has set. I put wedges under the support legs so that I could remove the wedge and had some room to get the legs out. I will post a photo of my forms.

Good luck with the pour. Lots of work by hand and not much less with a mixer.

David

[gugahulk]

Re: Work of Love and Passion... Miami FL

Hello

You need plenty of support under the forms and for the sides of the forms as well. Wet concrete is heavy and you do not want a blowout.
David

This is my biggest fear. I think I have enough but how do you know? If this things blowout I would die.... LOL Did you see the photos? by what you see do I have enough? What do you think? I also placed 2 bricks under every support legs so I can remove them easily.

HELP, HELP, and more HELP
Concrete mixing I HATE. So I am asking a few buddies to give me a hand and plan on renting a concrete mixer for the pour but it still a B!%$# to do. I am quite nervous about this one. I've done some concrete tables before but nothing this size. This thing is a monster next to my 2 other creations. Totally Freaking OUT!!!! LOL....

[Gulf]

Re: Work of Love and Passion... Miami FL

This is my biggest fear. I think I have enough but how do you know? If this things blowout I would die.... LOL Did you see the photos? by what you see do I have enough? What do you think? I also placed 2 bricks under every support legs so I can remove them easily. ...............

The brick under the supports may seem easy to remove now. But, when the full weight of the concrete hearth is on them, they will not. The wedges that, David is recomending, serve more that one purpose. They not only allow for easy removal of vertical supports. They also help keep from introducing unnecessary stresses on green concrete when removing the posts. If you have to knock them to the side for removal, you are also jacking the form up slightly. When the post finally gives way laterally, the deck is also falling slightly, but abruptly. That will not be a problem on a 28 day cure, but many on this site seem to want to remove vertical forms too early imo.

A pic from underneath the form will help.

[mrchipster]

Re: Work of Love and Passion... Miami FL

Base getting ready for concrete. Please any advice would be great. See the pictures below and if I am doing anything wrong now is the time... :-) Look forward to any comments.

I would add an expansion joint between your new slab and the Brasilian BBQ where the new concrete meets the old brick. It could be a piece of 1/4 inch ply that you slide out later and fill with caulk rope then caulk or sheet expansion joint foam prior to the pour.

[mrchipster]

Re: Work of Love and Passion... Miami FL

I have done this before and it worked well for me.

I used 4x4 verticals cut at about a 20 degree angle. Then add ply or solid wood plates to each side and attach with screws.

When your concerte forms need to come off, unscrew the plates and the support beam will come apart easily.

It slope of the cut needs to be shallow because you still want the load transferred vertically as much as possible. A steep angle will allow the 4x4 to buckle.

I have not tried this with anything smaller than a 4x4 so use your own judgement regarding applicability to your project.

I show the cut in the middle of the beam but I actually had it close to the top to also reduce the tendency to buckle.

For extra support you could add plates on all 4 sides

[gugahulk]

Re: Work of Love and Passion... Miami FL

I would add an expansion joint between your new slab and the Brasilian BBQ where the new concrete meets the old brick. It could be a piece of 1/4 inch ply that you slide out later and fill with caulk rope then caulk or sheet expansion joint foam prior to the pour.

Thanks for the advice Chip, you really think its necessary? I will go with what you say but that did not even cross my mind. What is the worst case scenario if I don't do this? What could happen?

[gugahulk]

Re: Work of Love and Passion... Miami FL

I have done this before and it worked well for me.

I used 4x4 verticals cut at about a 20 degree angle. Then add ply or solid wood plates to each side and attach with screws.

When your concerte forms need to come off, unscrew the plates and the support beam will come apart easily.

It slope of the cut needs to be shallow because you still want the load transferred vertically as much as possible. A steep angle will allow the 4x4 to buckle.

I have not tried this with anything smaller than a 4x4 so use your own judgement regarding applicability to your project.

I show the cut in the middle of the beam but I actually had it close to the top to also reduce the tendency to buckle.

For extra support you could add plates on all 4 sides

This is a great idea, I should have done this before anything. But looks like so much work now... I am going to rethink it. It seems like everyone is thinking its going to be hard to remove the forms once slab is cured. What do you think?

[gugahulk]

Re: Work of Love and Passion... Miami FL

Hello
I put wedges under the support legs so that I could remove the wedge and had some room to get the legs out. I will post a photo of my forms.

Good luck with the pour. Lots of work by hand and not much less with a mixer.

David

David can you give me an example of the wedges you are talking about? I have no clue what those are or look like.