Insulation question....again

[70chevelle]

I'm not sure if it's too technical a question, but I can't seem to get an answer, so I'll try again.

1) Is it a problem to put the FB Blanket on top of Vermicrete? It would make for an easier install if I filled few voids with vermicrete and then applied the FB Blanket. I have the vent complete and the exterior arch complete, but no pic. The area I'm looking to add the vermicrete is at the lower arch, instead of forming the blanket to the way that it is in the picture.

2) If you had to choose between the 2 (as I do), would you:
a) Cover entire structure with 1" FB Blanket and then 3"-4" of vermicrete; or
b) Pour the side walls & rear wall (barrel vault) with 4" of vermicrete and use 3" of FB Blanket on the dome only.

If you can imagine from the pic below: the brick is going to continue up to the where the dome starts. The area between the oven wall and the exterior wall is going to be filled one of the 2 ways above. My initial thoughts are to go with b), but am looking for other views. By the way, my budget is at $0 so buying a couple more blankets is out of the question, so I'm really looking for the best option from above

[rlf5]

1) There's no problem putting the vermicrete on first, but your oven will be less efficient. You really want your best insulator to go on first, but it shouldn't harm anything if you don't do it that way.

2) I like option B

[70chevelle]

rlf5 - thanks! I could form the blanket first and then put some vermicrete on to keep it in place.

[Groves]

nice short barrel, can't wait to see it in action.

[christo]

What kind of enclosure do you have planned?

If you are going the metal stud/concrete board (house type) enclosure - I'd go for 1 inch of ceramic insulation all around with a back fill of loose vermiculite or perlite. Just make sure any holes are filled in before you pour the loose stuff!

Christo

[70chevelle]

Groves - thanks, me neither. I've had one small fire in it so far, and plan on another tonite, after I'm done laying some brick (exterior)

Christo - I'm going to carry the brick up to the same level as the sidewalls of the oven. The top of the oven will have 3" of blanket, some vermicrete, then the stucco in the barrel vault shape. I'm going to carry the brick up the front on either side of the oven opening and have another hearth stone on top. Not sure if the chimney(s) are going to be stucco or brick yet. I'll take a few new pics tonite, it should at least be laid out.

On another note, I had a "T" and "'08" blasted into the keystone in the entryway arch. It looks pretty cool. Can't wait to finish. I'm going to try to get most of the work done this weekend, including my curing fires, so I can make some pizza's next Saturday. I'm having about 40 people over for a summer get together.

[Groves]

nothing like a deadline to speed the work up, huh.

How do you think your side walls will hold up without any buttressing? Seems like the barrel arch will be pushing the tops of those walls out with some force.

[70chevelle]

There will be lateral support once the brick sidewalls are brought up to the oven sidewall height. Then it will be filled with vermicrete or just vermiculite. I think it will hold up very well!

[70chevelle]

Here's a real time photo of my second fire.



Tomorrow, my buddy is coming to help lay up the sides,and hopefully I'll have it buttoned up by the weekend.

Here's another look



I'm definitely not having any issues with the draft.