42” Pompeii in San Felipe, MX

[modified9v]

JR... The stand is a bit large as I had intended on a larger landing. Also, was planning on the dog house too... over all the oven will not sit directly on the wall, but in just a bit. Not much.

Gulf... yes, the concrete here seems too always look dry after a day... sort of a powdery look. Light grey. Looking at it this morning is does have more of a wet look. Another reason may be the “cream” on top or just a bad picture... but it isn’t like the concrete I’ve poured in the States. As far as the footer, well it is 16” deep and tied into the block wall footer. Lot’s of 1/2” rebar. I will add that the way they bend the rebar here is different than anything else I’ve seen. I asked the conctractor about it and he said that this foundation was done just like all the houses are done here. They are still standing, but still much different than I’ve seen. I think we are good on that.

He should have the steel installed on Monday, which means Wednesday or Thursday (Manana, manana). After that, how long should I wait before I can start with my floor and dome?

Oh, just wanted to add that the heat index the day this was poured was 122f. Very high dew point as of late.

Thanks guys for the help and following along, Mikie V.

[Gulf]

In your pics, I don't see anything that remotely resembles a wet concrete color. Since you are having problems with the hearth slab, are you confident with the foundation and footers that are under the oven stand? If it is substandard, all the steel supports that your contractor recommends ain't going to help very much imo.

[JRPizza]

Something to consider - other than the floor bricks, most of the weight is concentrated in the circle of the dome bricks, and outboard of that if you build a doghouse structure. If you right-sized your stand the majority of the load should be over your walls except for the wood storage opening.

[modified9v]

I just met with the contractor at the build site and he agrees that we have a problem. Concern is that as the oven get heavier, the slab will sag even more and it will comprise mortar joints on the lower courses and they could crack. His solution is to put a heavy duty steal frame under the slab and attach it to the sides of the dry stack.

After that we will put a thin coat of stucco on the slab to make it flat and level.

Wish me luck, Mikie V.

[modified9v]

Update: Well, the slab was removed and the forms were rebuilt.. they poured it yesterday. These guys have a very difficult time following instructions. I will say that I’m not at all happy with the way it came out and I’m looking for solutions.The only thing better this time is that the material they used to make the concrete looked much better and they used even more rebar. It is also 2” thicker (now almost 6”). The thicker deal may have been part of the problem this time. I don’t think the forms under the slab were strong enough to hold the weight of the additional concrete and overnight it has sagged in the middle where there was no reinforcement.

In the photo with the level you can see to the right just how much it sagged. In the other photo you can see a sample of a typical crack that has formed as well. The cracking runs nearly the entire length of the pour on both sides of the reinforcement below the slab. The cracks were present last night when I hit the sack but grew overnight.

Options: Well, I can have them rip it out and get my money back and do it myself. Have them try again (not gonna happen). Once the forms are removed I could put a permanent reinforcement under the suspect areas... Or I could just say screw it and build the oven on top of this monster.

Do I think it will collapse? No. Do I think it could sag more? Yes, and that could be bad for the oven.

Questions: Would you build a Pompeii oven on this stand? What might you do?

Thanks, from a very frustrated Mikie V.

[modified9v]

So the center section busted up. Where I have the arrows on the pic is where they have been chipping away. It’s been slow going for a few hours now. When they busted off the overhanging part above the arched opening I was worried they could weaken it... not a chance. That baby is loaded with steal and the mix was real good. That stuff came out of a cement truck. Big difference in the quality of the concrete.

I think they will have the demo done and framed for a pour by this evening.

Mikie V.

[modified9v]

Wellll, what took all day to make took only 15 minutes to destroy. There is virtually no aggregate in the mix. Very little sand or rock. They are pulverizing it with little two pound hammers and chisels. Nothing stuck to the rebar. So sad.

[modified9v]

Thanks for the response guys... yes, the contractor is covering the costs to re-do it. Still not a good situation as it will set me back as far as time is concerned. I totally agree that had they formed it correctly I wouldn’t have had to lay down a 3/4” thick leveling material. That was going to be stucco on top of the scored concrete.

As far as to why it failed... I have never been impressed with small town Mexico concrete. In the third picture is how they do the sand. It is basically dirt that is run through a screen... the dirt is not washed. Also, the slab was not kept wet after the pour. It is my understanding that the slab should have been kept wet and covered for 7 day after the pour. It was not. Also should note that the thing is loaded with rebar... both 1/2 and 3/8. Probably wouldn’t collapse but why take the chance. I’m mean even the contractor said it was garbage.

Anyway, it will all work out and I won’t be out any extra cash so that is good. Things happened for a reason. I pretty sure they will get it right this time. I was not on site when they did the pour last time, but I will this time. I am going to suggest that my carpenter and I do the framing of the forms. I think I’m going to have them NOT finish it with a trowel. I think the trowel work is why the thing wasn’t flat in the first place. I’m thinking that a rough surface might give the FB board something to bite into.

Oh, and thanks Gulf, resizing pics seemed to make it easier to upload pics.

Mikie V.

[JRPizza]

Did your contractor give any theories about why the concrete didn't cure properly? Is he covering the cost of the tear down and re-pour?
If you build your forms right and finish off the surface after the pour you really should not have to do a secondary operation to level/true the hearth. You didn't post any pics of the forms prior to pouring, but lots of advice here on how much rebar, how thick to make the slab, and how to tie into your base. Now is the time to correct any design deficiencies and make any improvements you want in size/height of your slab. Make lemonade out of lemons.

[Gulf]

Try and resize the pics and see it they will upload. It will help for me to understand the thickness that you are pouring to level the stand or hearth? I'm also not sure exactly what cement you are using? You mentioned above about a stucco mix and then a portland and sand recipe?

[modified9v]

Well, major setback today. My carpenter and I formed the base to lay a coat of stucco to level and true the base so I can start building. We got it all formed up and it was really, really good. We decided to score the concerte base to give the stucco a better chance to adhere. My contractor climbed up on the base and it started cracking as soon as he started to score it. He was using a wire wheel on an angle grinder... not a very aggressive wire wheel. The concrete was coming off way too easy. As a matter of fact you could score it with a finger nail. Concrete was nooooo gooooood. Contacted the contractor and he came and looked at it. He said it needed torn out and completely replaced and I agreed. This time my carpenter and I will frame up the form. Ughhhh, glad we made the decision to redo it now before we got too far along.


Question, how long do I need to let the bas cure before I begin the build?

I tried to upload a picture but pics won’t upload right now for some reason.

Thanks for following along, Mikie V.

[modified9v]

JR, the pic is exactly what I needed to see. Between you and Utah you have given me what I need. Really glad you took a lot of pics. I need to take a lesson.

[JRPizza]

I think you have it. I might have been a little closer to the center of the oven with my arch - see pic below - it's a better view than the one I previously attached. If you are too far out from oven center you will have a point where the dome slope and oven ID intersect very low on the TDC brick, and if you are too far inboard the point will be near the top of the brick. Mine came out just below the centerline of the brick. I "think" it is good to shoot for an intersection point about 2" up to match the thickness of a brick laid on it's side.

[modified9v]

Probably should have taken the day off from working on this project. Ya ever feel like nothing is going right? Are you treading water with no end in sight? Can’t sleep?

This thing with the arch is obviously kicking my behind, but that ain’t all. My base. Ughhhh!!!! Let me back up a little... We started this whole project with a perimeter wall. I hired a local contractor to do this. Keep in mind I live in Mexico. It was a big project. I had told the contractor about the pizza oven and showed him the plans. He offered to build the base and pour the slab that goes under the floor. I told him use super strong concrete, a ton of rebar and make it flat... I must have mentioned the “FLAT” thing a gazillion times. Now I know they used a bunch of rebar cuz I watched them lay it out, Shoot, the oven could rest on the steel alone. But the concrete is crap. And, it is anything but level. I didn’t realize just how bad it was until I ran a big long straight edge across it six ways from Sunday.

I had mentioned that the slab was off in a previous post when I asked if stucco could be used to level it out. There was a suggestion for fireclay and sand. This thing is so far out that I’d use up too much fireclay. Keep in mind I have to cross the border twice and it’s an all day trip to get more. Hence stucco. Everything here is stucco or plaster. Next character to enter the mix is my carpenter. While everything else is going on around here, changing windows (bigger and energy efficient ), new counters, insulation, a/c ( mini-splits) being moved or installed, solar work... oh, and I had to add another sink in the kitchen... yadda yadda... anyway I hired a carpenter to build all brand new cabinets in the kitchen and bar area. He is an amazing guy (he has taken over my garage). He had a solution to the hearth slab being out of whack. His idea was to level one edge to start with a 1” strip of concrete laid on top of the slab on one edge... then, shoot a level to the other side and do the same thing... had to knock down some big high spots (used a sharp axe with little taps. Came right off. The idea was if we had 2 edges that were level to one another we could pour a loose mix in between and scrett it with the straight edge... here we go. I’m likin’ it...

I have attached a picture of one of the very custom kitchen cabinets my carpenter is building for me. Super cool.

We mix 1 part Portland to 3 part sand, just add water they said... LOL. It didn’t stick. It was a crumbling mess. Not sure what to do next, but my carpenter said “I have idea”... he will tell me about it tomorrow. Ahahahaha... maybe someone else has a better idea. Gotta love doing work in Mexico where nothing is square, level or plumb.

Sorry for the rant... tequila time,
Mikie V.

[modified9v]

Ahhhh, OK... pretty sure I’m following you. Basically every brick, although they may have the same angle, will not work from side to side? I see that I will have to work them one at a time to get a sweet fit... I suspect the same will be true with each dome brick that intersects the arch???

The thing that has had be stumped is how far in do I need to be to make that dome brick (the one I drew on that TDC arch brick) so it will make complete contact with the TDC arch brick. In other words, if I were to move that TDC brick further away from the center of the dome the IT would not reach it and I wouldn’t find out until it was too late and I’d have a mess on my hands. From what I can tell, by the time I reach that TDC the dome will not have come in too far to leave me with no where to place that dome brick. I hope I’m making sense with this. I clamped a dome brick to the IT and simulated that dome... that is how I came up with thinking I’m ok with the position of the arch form/template.

Does that make sense? If so, do you think I’m gonna make it with where I have it positioned now. Man, once I get this I think I will be off to the races. I’m probably making this wayyyy more complicated than it is and once past this hurdle I will laugh about it. I just don’t wanna screw this part up... I feel it is the crux.

Thanks, Mikie V.