The hearth questions and progress pictures

[dmun]

Re: The hearth questions and progress pictures

Most things in life are a time/money compromise. Since vermiculite and portland aren't free, I think the advantage tilts to insulation boards. You might look into insblock19, which may be available locally. That's what I used, and it works fine.

Check with local pottery and kiln suppliers, they might have it for less money than Harbison-Walker sells it for.

[DrakeRemoray]

Re: The hearth questions and progress pictures

I did not have any trouble getting a level floor using a wet fireclay mix troweled on with a tile setting trowel on top of my vermiculite layer. That said, I am sure it would be even easier using FB board.

Although I've not really had any issues, I will second Dave's comments. I too only used Vermiculete under the hearth - 4" in my case. Never an issue making pizza, but the next day when I am slow roasting or smoking - the variance between dome and hearth is usually about 50 degrees (the hearth being cooler). I think using the board or simply more verm. under the hearth would go a long way in having closer temps.
RT

Ditto! I used vermiculite only and do find that my floor is about 50 degrees cooler the next day, but I have always attributed that to the fact that the floor has less mass than the dome...

Drake

[George T]

Re: The hearth questions and progress pictures

Thanks for the thoughts. I poured my Perlcrete today. I was thinking....only the thinkess of a 2x4...or 3.5 inches. Should I be concerned regarding not having a full 4 inches of Perlcrete? It seemed somewhat crumbly I hope it sets up. I think I got it good and level!

Thanks again for all the ideas. The forum is a great help. I will post some more pictures tomorrow. Work on the fireplace tomorrow.....hopefully start my igloo on Sunday.

[thebadger]

Re: The hearth questions and progress pictures

George T,

I only used a 2x4 as well (3.5") but I also used the cal sil board on top. I don't think you want to go to much less than 4 if you only using perlcrete... Not that it wouldn't be okay but you want to retain as much heat in the floor as possible.

It is strange stuff. As long as you stick to the formula you should be fine.

Look up the thread on hearth height. I have 4 courses of block plus an add'l 12" of material on top for a total height of ~41" and I wish my hearth was a little higher (I stand 5'10")

Thanks
Dick

[George T]

Re: The hearth questions and progress pictures

Test Photo.

<a href="http://picasaweb.google.com/ghtaylo/GeorgeTSPizzaOven/photo#5211852083667468338"><img src="http://lh5.ggpht.com/ghtaylo/SFQ320ThADI/AAAAAAAAAEs/iiVc9XTxfBI/s144/IMGP1871.JPG" /></a>

[George T]

Re: The hearth questions and progress pictures

pictures from today. Got the firepot completed on the fireplace and added another inch of perlcrete. Up to 4.5 inches now. Hopefully tomorrow I can start to cut my firebrick. I am trying to complete my igloo this week. Project is moving along. It has been fun, but I am wanting Pizza. The fireplace has really slowed my progress.

Thanks to a great forum it seems to be going well.

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

[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!

[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.

[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

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?

[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.

[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

[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]

[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.

[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