Wrong dimensions - Help!!

[Tscarborough]

Re: Wrong dimensions - Help!!

I have resisted posting, but the fact is you need to tear it out and start over. Not all of, just the "engine", the oven itself. You will end up spending as much to repair it, maintain, it and feed it as you would to do it right, so you may as well go ahead do it before you invest more in it.

I see it quite often with large, custom "designed" multi-opening fireplaces. They barely work when designed and built perfectly, and they are seldom done so.

As it often happens, since the problem does not become apparent until after owner occupation, there is a great amount of time and effort spent on trying to fix it. The final usual fix is either a tear out and redo, or a set of gas logs sitting in a gorgeous but non-functional and expensive piece of masonry.

[RTflorida]

Re: Wrong dimensions - Help!!

Peter,
YES vemiculite is that absorbant. Not to mention any concrete. Current example - my next door neighbor has asked for my assistance with the hardwood flooring in his living room that is wicking water through the 8" slab. Twice he has had the installer remove the flooring and seal the slab...to no avail. I have contacted the manufacturer and basically have one option other than telling him to rip it all up and put a vinyl underlayment under.
Also have experienced a saturated oven, to the point where the vermicrete/support slab was weeping water at a pretty good rate. The firebrick dome and dome insulation wicked water from the hearth up to a height of about 2/3 of the dome height.

As for assistance with your problem, I have none. From everything I have read it sounds like a do over. Sounds like you have tons invested (a shame) and 3 courses of action:

Let your mason attempt any/all of the above fixes (at his expense). You have nothing to lose except time. You may get lucky, but I think one of you will get fed up an say enough. I think you simply have too much wrong, and all of the options are band aids. BUT, as long as you have the time and patience and it is not on your dime, give the bad aids a try.

Tear it all down, get an actual oven builder, NOT just a mason. The key is getting this thing away from that hillside. No disrespect, that is a common sense thing that anyone with basic masonry knowledge would/should have instantly seen. I'm afraid it is going to cost you, unless you seek restitution (sue) from the mason.

Money obviously being an issue at this point, tear it down (carefully), saving as many bricks as possible, and rebuild it yourself. To me, this is your best option. Unless you are physically handicapped (I hope I said that politically correct), this will be the most cost effective and will insure it is done the way you want. This forum proves that ANYONE can build a beautiful oven. Even with no experience you could duplicate what your mason has done (but correctly this time). Masonry is not difficult as long as you can visualize what you want and can use basic tools.

I know I have not been much help, and from the options mentioned by other members, no one has......Please understand, your issues are multiple and most have not been experienced at your level. Most certainly, no one has experienced a combination of errors such as yours.

RT

[lwood]

Re: Wrong dimensions - Help!!

Peter,
The first thing you need to do is adjust the resolution on your camera so you can post the pictures yourself. We need pictures with the explanation not three days later. Next, That mason has too much history with this project already. He will just be an interference. Get a new set of eyes on the project and deal with the old mason separately.

I told you the excavating would not be easy. You may even have to remove the exterior finish around the concrete oven slab, COMPLETELY. Get over the hope that you can do this without excavating everything underneath the oven, because you can't. I know you would like to preserve as mush as possible, but that whole front arch structure may have to come down in order to get to the slab. Get another mason to look at it and figure out how that can be done. Believe me, a knowledgeable mason will be able to do what I am proposing. You may not like what they have to tear down but it all can be re-done.

The 2" concrete slab gives me concern. I question whether or not it can structurally hold the weight of the oven as a suspended slab. 2" is not much concrete. But we will assume it will and proceed.

Get another mason to give you a quote on doing the excavation and we will proceed from there.

[brickie in oz]

Re: Wrong dimensions - Help!!

Some more pics from Peter.

Pic 1
Looking down: dome sits on slab (see corner of slab sticking out)

Pic 2
Other side, same thing:

Pic 3
Space between 1 inch thick wire-stucco retaining wall and oven (paint roller stick for size ref). Welded sheet metal collage is decorative on stucco upper rim:

[brickie in oz]

Re: Wrong dimensions - Help!!

More pics from Peter.

Pic 4
Overview from rear

Pic 5
Sloped mortar drainage slot passes by the slab, to out front of oven (looking straight down)

Pic 6
and pours out through holes, out in front of whole structure like a little waterfall, down into drainage swale and away (goes beneath fireplace bridge). By the way, slab and vermiclite are behind fireplace wall, like 2nd and 3rd + 1/2 bricks down from hinged oven door.

[Tenorio74]

Re: Wrong dimensions - Help!!

Peter,

Just read this. I agree with most comments here, and I see only 2 options.

1. Complete tear-down / re-build. You will save money in the long run with wood costs.

2. Remove brick floor and create a new floor about 30 cms above existing vermiculite layer. I have attached a sketch of what might be a solution (hope you understand it - I don't do 3D renders or stuff). Your oven is tall enough to raise the floor as suggested elsewhere. Block the inner flue, and keep the outer one, use it like a primavera oven. If you calculate your distances, you should end up with a nice 20" high oven.

After the raise, you will need to make a proper door with a 63% ratio.

Whatever you choose, it will be work, just like everyone chiming in thinking of how to fix it.

I get your greif. Lucky it's for home use. My guy #%!$&-up my oven floor and delayed my whole project 2 weeks. Bite the bullet.

[Tenorio74]

Re: Wrong dimensions - Help!!

PS. Its hard working inside a closed oven, but not impossible.

[lwood]

Re: Wrong dimensions - Help!!

I like that solution, still a lot of work. Basically, tear out the the existing fire-brick floor and build back up from there leaving a 2" gap under the new floor. Your going to raise the floor by 8"? 2" air gap plus 2" concrete slab plus 4" vermiculite/concrete, then replace the fire-brick floor. Do you have 8" to play with?

[Tenorio74]

Re: Wrong dimensions - Help!!

I like that solution, still a lot of work. Basically, tear out the the existing fire-brick floor and build back up from there leaving a 2" gap under the new floor. Your going to raise the floor by 8"? 2" air gap plus 2" concrete slab plus 4" vermiculite/concrete, then replace the fire-brick floor. Do you have 8" to play with?

Hey Lwood,

He said that his oven was about 30 inches high.... You can easily take away 8", even more. My 51 is 18" high.... Any takers?

There isn't so much material as there is manual labour.... so maybe his contractor will do it for the remainder of his fee.

Or he can do it himself and use the remaining $ for materials and red bull....

[roobqn]

Re: Wrong dimensions - Help!!

That is a brilliant solution and maybe the most viable outside of tearing the entire thing out. Will the existing walls wick moisture up from the existing base to continue creating problems though?

[Tenorio74]

Re: Wrong dimensions - Help!!

Will the existing walls wick moisture up from the existing base to continue creating problems though?

I guess it should be minimal. If you want to get serious though, you could use a steel bar instead of the middle support wall (won't transfer any moisture), and use a giant steel o-ring under slab where it is in contact with the new "floating" hearth, as a moisture shield.

I think decent regular firings should control the rest of moisture trying to come in the gap laft on the outer ring.... But it will be nothing compared to what's going in now!

[lwood]

Re: Wrong dimensions - Help!!

With a 15" door height opening. That leaves a 7" door height. You need almost a 14" door ht for that dome ht to get the 63%. Will need to modify the door opening also. Maybe you will get some wicking, but this is much better.

[peterthewolf]

Re: Wrong dimensions - Help!!

Tenorio, welcome to the growing list of !!Thank You's!!. The drawing helps understand. For any of you guys who may think I'm being a jerk to hold out past what I've so far explained, it's a learning curve going on here with your help. If our guy had followed the plans, at least in true concept even if not completely literal design, I wouldn't be getting a degree in thermal building dynamics in your university right now.

Ok, I just edited this post and condensed it - go ahead to the next one.

[peterthewolf]

Re: Wrong dimensions - Help!!

So, a few things. First, the door has an embedded metal lintel, so I think it ought to stay put as that's structural, and the door hinge is actually welded to a 3/4" pole that goes up into a pipe in the brick structure (sorry) that was a bit of an afterthought for the guy after it should have gone instead into a simple metal protruding ring at the front. That's what is under the double-bulging copper unit above the door. It's that structure that is up on the left behind the copper sheet, but I think in an earlier photo the copper wasn't there yet so you can see it. The right copper one is hollow but only bulging out there in design to mimic the left brick protrusion so it isn't ugly. The bottom of that hinge pole is buried around 8 to 10 inches below and swings inside a slightly wider pipe on a disc of stainless down there. So the door is likely a structural keeper at 15x15.

Next Q: I get it about the airspace. Cool. Would that 2" airspace replace the vermiculite below it essentially by breaking contact with it with a new slab? How about not another slab but just doing airspace with strong fiberboard with say, some rebar laid beneath it to give regularly space "ribbing" support like bed slats? Gosh, sorry, what is fiberboard exactly & does it have other names? I take it this is a non moisture conducting sheet medium that may heat up through the floor but not transfer it to a cold wet surface below - especially if air not contact is below it, right? I keep thinking that the joint area at floor meets dome base is least important of all. Could this be true?

Q: A little less height than 15" is ok for the door; we still can get a big bird or creature in there perhaps. But instead of raising the floor so high, what about that step of eating 8 inches up from that peaked dome top by simply bolting a round ceramic kiln shelf with stainless bolts and brackets (say, 3 or 4 of them), after stuffing some non toxic insulation up in that space at the peak behind it? Thus the inches would be taken care of for 63%, the 40 inch existing floor wouldn't turn into 36 or less by moving upward in the cone. This shape above certainly wouldn't be convex, but hey, now it is a bit pointy up there in contrast to the Pompeii plans (like 2 times pointy). The good news if that can be done is that the flat "cap" up there would be exactly in the most problematic angle, and heat from walls going up would certainly be in a hurry to cross it to get to the other side of the dome...the fire and heat arc above that would pound at the floor. So though it might not be as "heat mass retaining" - but even more heat *reflecting*, it would be the focal surface for all of the side heat - straight down pretty much. If so this could be really easy. If this might work up there, we could first try it by just holding one up there with kiln shelf supports or something before committing to the bolts. What do you think about this dome top idea?

Ok, last: Why two inches into the walls? That's the supporting depth of the bricks, about. Concerns me. Since the walls are insulated well and sitting on the raised slab, (not the ground) couldn't we just dig out the floor *within* the dome inside walls and be ok?

[peterthewolf]

Re: Wrong dimensions - Help!!

Peter,
The first thing you need to do is adjust the resolution on your camera so you can post the pictures yourself. We need pictures with the explanation not three days later. Next, That mason has too much history with this project already. He will just be an interference. Get a new set of eyes on the project and deal with the old mason separately.

I told you the excavating would not be easy. You may even have to remove the exterior finish around the concrete oven slab, COMPLETELY. Get over the hope that you can do this without excavating everything underneath the oven, because you can't. I know you would like to preserve as mush as possible, but that whole front arch structure may have to come down in order to get to the slab. Get another mason to look at it and figure out how that can be done. Believe me, a knowledgeable mason will be able to do what I am proposing. You may not like what they have to tear down but it all can be re-done.

The 2" concrete slab gives me concern. I question whether or not it can structurally hold the weight of the oven as a suspended slab. 2" is not much concrete. But we will assume it will and proceed.

Get another mason to give you a quote on doing the excavation and we will proceed from there.

Lwood, RT and Tscarborough - just read yours out of sequence. Great advice - I will absolutely get a mason to come out and evaluate this. It may be Monday or Tuesday and I'll get back to you on that part.

Sorry about the pics; I've been sending them over Brickie to load who's been a sport.

...actually, no, while I have a number of talents, I'm clear that I'd not be able to build it myself - this kind of thing is just not my skill set. As Clint said..."a man's got to know his limitations"... Damn, that's why we hired this man when he said of all things he does, this goes so far back in his career that it would be nothing for him to build one...essentially that it makes him an expert as we heard it. Perhaps if (these) plans were really followed, we would have benefitted from that.