New WFO in Asheville

[Robpriddy]

I have started an oven using the plans from Forno but I think I need some advice before moving on. Should have spent more time reading this great forum before starting work on the project.

The oven is built into a hill and there will be outdoor kitchen space for a gas grill, charcoal grill, stove and countertop space to the left of the oven. There will be a deck and firepit in front of the oven. The deck should be high enough so the 5 courses of blocks will not be too high. (I hope)

Foundation slab is poured and oven stand is built with no problems, just lots of work! I decided to frame the hearth using Hardibacker under 3 1/2" of concrete and lots of rebar for strength. I did the concrete pour Saturday morning with no problems. After lunch I poured the Vermiculite/Portland mix and that is where I ran into a problem.

It started clouding up as I began mixing Vermiculite and Portland and by the 4th bag of Vermiculite it was drizzling and looking like major rain so I was rushing. First problem..I ran about 1" short of enough material to fill the form so the insulation is only 3" instead of 4". Second problem...since the mix did not make the top of the form I had trouble leveling so the pour is not as flat as I would like. Third problem...my tarp was old and must have had a few holes which leaked resulting in bad places in the surface of the final pour.

I have a couple of ideas on how to move forward but some experienced advice would be helpful. I guess the most serious problem is lack of sufficient insulation and the surface issues are mostly cosmetic. I guess the easy solution is to make another Vermiculite/Portland pour to the top of the form and get it smooth this time. Anyone know if it will hold together if I add a second thin layer?

A more complicated and expensive approach could be to add FB board over the top of the Vermiculite and under the oven area only. Then raise the top of my form to the top of the FB board and do a concrete pour to the top of the form and top of the FB board. That should conpensate for any lack of insulation and give me another chance for a good flat surface.

Any ideas, suggestions, or recommendations would be greatly appreciated!!

[Laurentius]

Re: New WFO in Asheville

The answer to your first question is yes. Read, read again. The build is the easy part, understanding the principle of the science behind it will result in a successful functioning oven.

[texman]

Re: New WFO in Asheville

Hey Rob
Welcome and way to jump in and tackle that base. I would level your vcrete with more vcrete. I think it will "stick" just fine, just pack that stiff in there. I like the vcrete and fb board combined for the extra insulation. I will have to check the forum, but i think you need 5-6" of vcrete to equal 2" of FB board. So the thin layer probably needs to be a thick layer. I have seen it mentioned many times. You do not want concrete on top of FB board though. Either finish with vcrete and start you floor or the fb board. You want only insulating materials next to your brick oven. HTH and keep up the good work. Also, go ahead and post your pics full size, the forum will size them appropriately. Your pics are hurting my eyes to see.
Texman
I meant pack that STUFF in there (vcrete) no dead bodies in pizza ovens! They can't take the heat or the weight and the smell.

[Robpriddy]

Re: New WFO in Asheville

Many thanks for the feedback and encouragement. I am reading and learning and plan to jump back in with more vermiculite mix today to finish filling the form. That will give me 4" over the 3 1/2" of reinforced concrete.

Still learning about the picture procedures for this forum. At first I posted without pictures because I could not get them to upload. After reading I found a post that explained it and tried to load downsized JPEG files at about 1mb and got an error message that they were too large. These were downsized to about 60kb...really small. Sorry about your eyes, I'll try again.

[Robpriddy]

Re: New WFO in Asheville

Been tied up with work for the past 5 weeks so just got back to the oven project today. The 1" pour of Vermicrete did not stick. It is warping and separated from the first pour. It has also cracked in a couple of places. I do not think it will matter once the oven is holding it down and the finishing materials are covering the rest of it. I will just have to be careful with it until it is covered.

Cut my floor bricks today and did a layout of the floor with the first row of bricks for the walls. I am getting excited now! I have built the Indispensable Tool and hope to set the floor and start building the walls on Thursday and Friday.

I am struggling with the landing a little. I am going with 19" wide but don't know how deep the landing should be. The layout that I currently have allows for about 12 1/2" for the landing. Is that about right...any advice??

I read a post from someone who suggested separating the walls from the floor by the width of a piece of cardboard. They said that the cardboard spacer burned up with the first firing. Is this a recommended procedure to create a small gap between the floor and the oven wall?

All advice is appreciated!!

[Gulf]

Re: New WFO in Asheville

Origionally posted by Robpriddy

I read a post from someone who suggested separating the walls from the floor by the width of a piece of cardboard. They said that the cardboard spacer burned up with the first firing. Is this a recommended procedure to create a small gap between the floor and the oven wall?

Yes it is by many on this forum, including myself .

I'm a little concerned about

The 1" pour of Vermicrete did not stick. It is warping and separated from the first pour. It has also cracked in a couple of places.

Did you dampen the first pour before pouring the second? Did you keep that 1" layer covered to where it could cure slowly?

[Robpriddy]

Re: New WFO in Asheville

Great points...probably did not give it enough attention after the second pour. Thanks for the support and for the confirmation on the spacing between the walls and floor. Hope to get started in a couple of days.

[mrchipster]

Re: New WFO in Asheville

Another hint on the spacer for the floor, you will want to have some type of cover for the floor to keep it clean, so put the cover on before starting your dome and tape over the floor and down around the outside of the cardboard spacer. That way there will be no wet mortar that gets down into the joint and cause a problem. I used a heavy plastic 1/8 thick but ply or cardboard over plastic sheeting should work well also. I used 2 layers of corregated instead of one for my spacer but that may be overkill. Then again it was thin cardboard.

When making the floor covering make sure you have a way to remove it, I cut my plastic into 3 pieces and then taped it back together so I could fold it up and slide it out the door when the oven dome was complete.

Chip

[mrchipster]

Re: New WFO in Asheville

These were downsized to about 60kb...really small. Sorry about your eyes, I'll try again.

You should be able to change the quality - resolution settings on your camera when taking the photos that way you will not need to do the extra step of reducing them, I find that 1024/768 or 640/480 to be good for uploading.

Chip

[Laku]

Re: New WFO in Asheville

I would not mess with camera picture resolution, take them as large as you can. Reason being if you ever take a picture of something you'd like to get enlarged (you can't often tell in advance when you get something like that) it will be impossible from too small a picture. Reducing the size is easy, enlarging with good results practically impossible.

Just a friendly tip from a guy who works with images for his living.

[mrchipster]

Re: New WFO in Asheville

I would not mess with camera picture resolution, take them as large as you can. Reason being if you ever take a picture of something you'd like to get enlarged (you can't often tell in advance when you get something like that) it will be impossible from too small a picture. Reducing the size is easy, enlarging with good results practically impossible.

Just a friendly tip from a guy who works with images for his living.

Good idea if you are taking a photo with a lens larger than a dime but for most of us the pocket camera or phone is the primary photographic tool. And there is so much noise in the high resolution photos of a low cost camera very few are worthy of a blow-up.

But good advice for those of you who own real nice cameras with the proper lighting and are trained in the field of photography.

Chip

[deejayoh]

Re: New WFO in Asheville

I am struggling with the landing a little. I am going with 19" wide but don't know how deep the landing should be. The layout that I currently have allows for about 12 1/2" for the landing. Is that about right...any advice??

Do you mean 12 1/2" for the vent? or do you mean the vent + the landing?

My experience, 12 1/2" is pretty deep vent - especially if you are going to have a landing in front of it. My vent is 10" deep, with a 15" deep landing - and I would not want to have to reach much deeper in there for starting fires and such. Some builders prefer a deeper vent with a narrower landing, because it's easier to build the opening on a deeper vent. I you choose to go with a 12" vent, I would plan on a narrower landing.