Wrong dimensions - Help!!

[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.

[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.

[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:

[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.

[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

[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.

[Wiley]

Re: Wrong dimensions - Help!!

JAG, Thanks for posting the link.

If one were taking examples more akin to what we are dealing with in our finished WFOs the "cement" listing is perhaps the wrong one to take. I would think the the "concrete, stone" at 1.7 one might be more accurate to what we have in our WFOs. The listing for cement is a bit ambiguous (IMHO) in it doesn't state the condition of the cement, as in: "cement , powdered, dry, loose" or "cement, compressed to solid mass" or listing a moisture content of cement if they meant after it has been mixed with water and cured to a solid mass (and that would bring into all sorts of variables such as how much water when mixed and the moisture content of cured cement). One would think and expect that the latter (mixed solid mass or compressed to a solid mass) would have a thermal conductivity closer to the listing for concrete.

The listing for "concrete, stone" at 1.7 is closer to the listing for "cement, mortar" at 1.73.

bests,
Wiley

[brickie in oz]

Re: Wrong dimensions - Help!!

Brickie would you mind once more if I send you photos to post?

Sure, go ahead.

[peterthewolf]

Re: Wrong dimensions - Help!!

Hey- now we're talking! Roobqun, lwood thanks. I'll clarify those specs here, and just took some photos. Brickie hang in there with me. Because we did spend a ton, and I prefer not to go through the hassle of getting the money back or spending it again, I would like to see if we could discover our way out if it is possible. So thanks for your patience in this process. If it ends up a failure, at least we can say we tried.

Brickie would you mind once more if I send you photos to post? It's not working from here. I just took photos of the slab on which the oven sits (back corners stick out so you can see it), of the drainage for surface and subsurface water, and of the narrow channel that is between the dome and the hillside that we dug out and stucco'd for view of the retaining wall and space.

Details: Yes, the slab is reinforced, with rebar. The ground it sits on is sandy clay: a soft moisture conducting sandstone which can be wet in winter. It's not the easiest thing to dig, but a pick takes out chunks per stroke. It is almost rock hard in summer. The oven is not "into" the hillside - no side contact. That stucco around it with the sheet metal decoration is essentially a retaining wall on 3 sides. We dug an area larger than what the whole oven would occupy. Then we left a "slot" around the oven like a horseshoe for any water on the surface to travel around downgrade to the drainage that is below the whole structure.

The slab is two inches thick from ground up, sitting on that clay. The vermiculite is 4 inches thick, sitting on top of the slab. That all was done in a 2x6 mold. I think it was half an inch of mortar, just for brick setting, on top of that, onto which the brick floor was set. The bricks are set flat, so the brick floor is one brick thickness, about 2.5 inches, pushed together without mortar between them on the mortar bed. So there (are) at least two inches between water on or in the ground, and the vermiculite.

Is vermiculite *that* absorbent, that it would suck water vertically upward from the flat surface of the two inch slab beneath it and wick itself upward to saturation? It was 5 parts vermiculite and one part portland. It may have been 4:1.

It appears to me that the brick dome also began (on top of) that slab, and built upward from there. In the pictures you'll see that the rock dome goes lower and touches the narrow water draining channel below, but that rock is pretty non porous, and even if slightly so only small contact points from rock to rock are there. But it's the setting grout - a lot of it between the rocks - that is porous, and that goes down. I don't believe any of it sits just on earth. If so, only the mortar between external rocks touches at the bottom, and that would be only where (if) it is not on the slab.

As you can see from the paint roller handle set into the channel for size reference, there is not room to get in there to excavate further out into the hill for drains. For that, we'd have to go outside, around it, as it is all stucco/wire...and a fun sheet metal sculpture that is *all* welded together. So we're holding on that idea so far but not out of the question to hire a couple of labor folks to dig a body-wide channel around that and down a little.

Yes, roobqn we did send a letter, saying please fix it to the point that it works, and burns efficiently like ovens in the plans do (average feedback I am getting is 3 to 8 wrist sized sticks brings it up, and only a few sticks maintains it hot - all with the door open). Certainly this guy is capable of doing these things - according to our directions since it has now been necessary to go back and do this research and consulting. If he is unwilling or unable to accomplish the result after our time limit is reached, then we will use remaining funds to get someone else. Judging by our last face to face conversation, we do not know if he will be willing, or will walk. Que sera sera. We have given a couple of weeks, which is good for brainstorming.

Last, I could see somehow *drilling* beneath the slab horizontally through the brick face of the low fireplace to get under the slab, but it would be an impossible *dig* to get back under there. The only way to get under that slab the way it is set back into the hillside is straight back from the patio, and at that it would be about 7 feet back through an opening that could only be say, 1 x 1.5 feet through the back of the fireplace which sits beneath the oven's cooling shelf.

lwood, we are in Sebastopol, a hour North of the Golden Gate Bridge, near Santa Rosa. Are any of you guys local?

[JAG]

Re: Wrong dimensions - Help!!

Just for the record. FWIW.

Note the conductivity


glass-1.05
glass window is-.95
vermiculite -058
Portland cement-.029


Thermal Conductivity of some common Materials


JG

[roobqn]

Re: Wrong dimensions - Help!!

Yes, we built it into the hill. We dug back, leveled, left space at the corners about one foot, and where the dome bulges out to meet flat hill angles, only a few inches. We stuccoed the hill cuts onto wire mesh and left no exposed dirt first. We mortared that ground around with a slight flow out toward each front side of the whole structure to channel water. Look for a little black circle at your kneecap height on the right side of the picture. That's a short piece of black 3 inch flex drain through the half wall, so rain water can exit forward and away. Yes, this hillside holds and dispenses a tremendous amount of water in Winter. The cement bulge of ground that you can see at the base of the whole structure in front is a 1 foot wide open swale that runs all around the base of the hill to carry water away in the rains. The fireplace floor is bridged over it. From both seepage and real flow from gopher sized holes punched in the stucco retaining wall all along the hill into the swale, much water can flow out from that hill. What on earth (pun) can we do - short of demo-ing and lifting up a *new* oven to counter absorption and heat sinking??

Peter

This sounds like the base is either already suspended off the ground OR at least partially dug out and a starting point to excavate further. Not sure which though.

The rest makes it sound as some excavating was done around the oven, but only to the point of the floor. Can it be dug out all the way around and the resulting cut out be replaced with a new retaining wall on all three sides? This would seperate the oven from the hillside.

In another post however, you said you sent the mason a letter that said in effect fix the oven as per the plans or loose the rest of the money. I would see what comes of that. Let him come out on his dime and follow the plans to the T. In effect making him demo the entire thing and rebuilding, that includes the base and sides. Unfortunetly that may cause him to walk away from the rest of the money leaving you where you are now. Might be a blessing.

[lwood]

Re: Wrong dimensions - Help!!

Peter, is there any way to excavate under the oven floor? If you can create an air space under the oven you might eliminate much of your problem. Let's try to save this thing. Where in Ca are you? What is the oven floor sitting on? Is the slab directly on the ground? What are the layers of masonry you have now, starting at the ground? Hopefully a steel reinforced slab of concrete, some vermiculite/concrete insulation, etc. Tell us, in detail, what all those layers are from the ground to the oven cooking surface, including thickness measurements. If the existing slab can support the rest of the oven, you can excavate just enough to build a structure underneath it. No guarantees about cracks and how easy it will be, but you can save most of the structure.

I'm afraid that as long as you are in direct contact with the ground, you will have a problem. And It appears you have it coming from three sides of the oven. The quick fix you are looking for is just not there. It's very difficult to really understand this issue remotely. Maybe there is an easier way, but from here it's hard to see it. Have you asked anyone else to look at the oven? Like an expert. Might try that.

I would do all the investigating you need to do to convince yourself of what to do. Drill holes, look at the vermiculite, whatever. Then if you are interested in trying the excavation I am proposing, I am happy to walk you through it, as well as many others on this site, I'm sure. You know Peter, the advice you get on this site is worth just exactly what you paid for it...nothing, unless you use it.

[brickie in oz]

Re: Wrong dimensions - Help!!

Peter, if it was me, and Ive been avoiding saying this, but I would cut my losses and do it all again properly, as I have done with my own oven.

http://www.fornobravo.com/forum/f44/oven-number-two-15241.html

David, we agree to disagree..

[david s]

Re: Wrong dimensions - Help!!

yes, I think that's what I'd try if it's easier than starting from scratch.

Brickie, if you add air to any material it becomes less dense and hence a better insulator. Hebel or AAC is a good example of this, it's made of concrete which is a poor insulator, but when full of air it becomes less dense (about a third the weight) and in turn becomes quite a good insulator.

[peterthewolf]

Re: Wrong dimensions - Help!!

David, Brickie-
Forgive this. Learning the process here as we go. Pull up the floor: Then glass, draining gravel, whatever: To build a pedestal of draining material an inch or two up on top of the existing 2 inch slab, then a thin (membrane) layer of mortar, then above it, vermiculite with brick on that...are you saying that with the several inches of drainage this could be ok? That means of course, ending up with a floor that is one brick thickness higher than now, to accomodate the draining layer on the existing slab below, but ok then. Is this an option?