The hearth questions and progress pictures

[stewpot]

Re: The hearth questions and progress pictures

George
I really like how your oven progresses
I am about to pour the concrete/vermiculite but seeing your photos I may go back and remove the top course of 9'' blocks, and replace with a course of 4''.
I was wondering how to protect the layer of vermiculite from the weather, this would solve the problem. Seems to be a lot of extra work,though.
Replacing the top course and pouring the base inside would reduce the height 9'' which may not be a bad thing as I,m going to finish up with oven floor at about 4'6'' as it is at the moment.

[asudavew]

Re: The hearth questions and progress pictures

Hey George,

I just finished up my chimney. I'll post some pics in a bit.
Basically it's a thin gauge metal pipe with a rectangular transition that I wrapped in chicken wire, and covered with high heat mortar. I just covered most of that with perclcrete insulation.

I think it turned out nicely and cost me... 25-30 bucks.


Dave

Oh.. I bought the pipe and transition at H/D

[George T]

Re: The hearth questions and progress pictures

Dutch. Thanks for the compliment. My nephew is a brick mason and I grew up working for my dad....also a mason....They do the real skill work.

Thanks dmun. I will have to try to track your pictures down to get a better idea. I am a bit pressed for time and I keep thinking although more expensive I might be better off to go with a duratech solution. Do you or anyone know if the straight lengths of the pipe can be cut to length or do you have to piece together based on preset lengths.

I was also was thinking about using single or double wall stove pipe....there are no combustibles and it is less expensive.....Thanks again everyone for your thoughts

[dmun]

Re: The hearth questions and progress pictures

I was thinking of going with a masonry flue tile, but I have to angle it back to get to the center of the structure. Not sure how I would provide the appropriate support for a complete masonry chimney.

I worked through this with my project, which has a two story two flue masonry chimney. What I did is to angle my flue tile back at 30 degrees until it was at the correct position for where I wanted the chimney to be. At this point the angled flue tile is supported by mounded up vermiculite concrete. When I got it to the place where I wanted it, i poured a support slab, basically a re-inforced concrete bridge, with vertical supports to the main hearth slab. I put a layer of insulating blanket around the flue tile before I poured the slab, so it wouldn't bind and stress the dome at that point. Up from there, I stacked up the flue tiles with refractory mortar, and built the chimney up from the secondary support, with the required min 1/2 inch air space around the flue tile.

I gave the process a lot of thought, and that's what I came up with. It may be a tad overbuilt, but a masonry chimney is a lot of weight.

[asudavew]

Re: The hearth questions and progress pictures

More progress on the fireplace today. Tomorrow I get to work on the WFO again. I also need to begin thinking about the chimney structure. I was thinking of going with a masonry flue tile, but I have to angle it back to get to the center of the structure. Not sure how I would provide the appropriate support for a complete masonry chimney....perhaps the Stainless steel would be better route to go.....lighter weight and require less extensive support. Anybody helped someone through this issue before?

Picuture updates below.

Just check out my thread.........
I went with a light weight chimney.
But... I have recently covered it with high heat mortar for a better draw.(fingers crossed)

[Dutchoven]

Re: The hearth questions and progress pictures

Nice brick and stone work George
Dutch

[Dutchoven]

Re: The hearth questions and progress pictures

After building his stand, he poured his vermicrete first. Then he poured concrete on top of that. I guess it ensures a level surface for floor...but not sure how insulating performance would be...and would the vermicrete start soughing off the bottom side of the hearth?

That is how I did mine because Alan Scott suggested that method as well...tremendous heat sink in the floor...takes a long time to get hot but then once it does its stays pretty hot for quite a while...in truth the vermicrete should be floating rather than shrouded in the concrete layer on top to be most efficient for that method of construction...I definitely would recommend the structural layer first and then insulate...
Best
Dutch

[George T]

Re: The hearth questions and progress pictures

More progress on the fireplace today. Tomorrow I get to work on the WFO again. I also need to begin thinking about the chimney structure. I was thinking of going with a masonry flue tile, but I have to angle it back to get to the center of the structure. Not sure how I would provide the appropriate support for a complete masonry chimney....perhaps the Stainless steel would be better route to go.....lighter weight and require less extensive support. Anybody helped someone through this issue before?

Picuture updates below.

[dmun]

Re: The hearth questions and progress pictures

After building his stand, he poured his vermicrete first. Then he poured concrete on top of that.

The original pompeii plans were exactly that: insulating concrete under the support slab. Experience showed that the floor took too long to heat up, it was hard to hold pizza heat, and the oven used too much wood. The two were in the process of switching when I started reading here. There was a transitional phase called the "island hearth" where a slug of concrete was buried under the hearth floor in the vermiculite mixture.

One of the bad things about the original plan was that the oven wasn't completely encapsulated in insulation: the heated part of the floor went all the way to the exterior. [/forumhistory]

[thebadger]

Re: The hearth questions and progress pictures

Cplain,

I would think you would want to pour the concrete first - 1) mainly for the supporting structure that spans the hearth and 2) to help insulate. The concrete is there to hold everything up and the insulating layer is there to insulate. Maybe someone else has some thoughts.

George,
Love the pics. Looks like you are making good progress. I think you'll be happy with the extra insulation. Looks like you did a good job leveling your bricks!

Dick

[cplain]

Re: The hearth questions and progress pictures

Came across a novel idea regarding heath/insulation layers. Guy posted his WFO building experience at:

Matt Considine : Building a brick oven

After building his stand, he poured his vermicrete first. Then he poured concrete on top of that. I guess it ensures a level surface for floor...but not sure how insulating performance would be...and would the vermicrete start soughing off the bottom side of the hearth?

He starts talking about it on his 23 August 2003 posting...just about picture #24.

The above mentioned website has a lot of good pictures of the entire build process.

[George T]

Re: The hearth questions and progress pictures

Good start on the Igloo and the arch. More work to do on the fireplace tomorrow....hopefully get close to finish of igloo on Sunday. Have to start traveling for work before long. Could stop the progress during the week. Thanks for all the help so far! What is the best way to tie in the arch? seems that the brick will be hanging in mid-air?

[George T]

Re: The hearth questions and progress pictures

Laid the cooking floor tonite. Went pretty smoothly. Thursday and Friday hope to get a good start on the igloo. I used a drymix on my perlcrete. used 2 parts sand and 1 part fireclay.....then watered the bricks down to get them to set.

I am debating the templates. I liked Les's single panel. Thought it could be a good help. Any conscensus on the easiest method?

All pictures... Picasa Web Albums - George - George T's Pi...

[George T]

Re: The hearth questions and progress pictures

Dmun....I agree. I tried that....my photo's are on picasa and the postcard gives me an error and says invalid file name. I am using the function in picasa that gives you the url to past into email or IM....

I am open to suggestions.

[dmun]

Re: The hearth questions and progress pictures

Hey George,

You're trying too hard: just hit the postcard icon above the message box, and paste in your picutre's URL.




The first one didn't look like a valid picture location. Is this what you meant?



That's one BIG rumford!