Sand instead of Vermiculite?

[jhobbs]

Since I live in Florida (and being a cheap bastard) I was wondering if there would be a big difference using sand instead vermiculite. I know the Romans didn't use Vermiculite. I do want to use the best possible conponents, but tring to keep cost down.

[egalecki]

Re: Sand instead of Vermiculite?

sand is not an insulator. You'll end up heating it up along with the oven. I expect the Romans had slaves to cut wood and fire up the ovens, but I sure don't!

[nissanneill]

Re: Sand instead of Vermiculite?

Hi jhobbs, and welcome aboard,
don't be a "cheap bastard" when it comes to insulation. This is the one thing that you should not compromise as it will determine how much time and wood to heat up and how long you can cook in it.
By all means, go cheap on your bricks, arches and final appearance, who cares what it looks like, you can always cover it up with a big box or enclosure, but you can't fix the insulation, especially under the hearth.
Do it right the first time!

Neill

[Dutchoven]

Re: Sand instead of Vermiculite?

I concur with the others...vermiculite is not so expensive...I have seen it in our area for about $25 for a 4 cubic foot bag...2 bags of that and a bag of portland and you've got a pretty good bit of insulation...not worth skimping on at all
I suspect the Romans may have used something like pumice and they also had a great deal of flyash hanging around in many places!
Best
Dutch

[RTflorida]

Re: Sand instead of Vermiculite?

We all know the Romans built thousands (probably millions) of ovens. We have NO idea what the thermal efficiency was of those ovens. They may have used a volcanic insulator or fly ash, but again we have no idea how well their mix may have worked. I'm betting they had minions stoking the fires all day, consuming a lot of wood. The old adage - "do as the Romans did", just doesn't make sense to follow literally and completely.

As I have told others, I have around $125 in all of my insulation - 2 four cubic ft. bags of vermiculite - $17.95 each, 2 four cubic ft. bags or perlite - $18.99 each, a 25 sq ft roll of 2" ceramic blanket - $20 plus $19.50 for shipping (was a great deal on ebay), and 2 bags or portland (around $10 a bag). The result is 4" of vermicrete under the hearth,
2" of blanket on the dome, and 3" of perlcrete on top of the blanket.
Prices do vary; but if you are going to splurge on one thing, it has to be the insulation. There are literally dozens of posts from people who have joined the forum looking for help in adding insulation after the fact.....it can be done with some success, but why go there if you know better before you build. Being a cheap bastard is one thing(I've been known to be one on many occasions); being a stubborn, d--b, cheap bastard is another.

Treat yourself to a well functioning oven, its a lot of work building one, you deserve it.

RT

[james]

Re: Sand instead of Vermiculite?

Since I live in Florida (and being a cheap bastard) I was wondering if there would be a big difference using sand instead vermiculite. I know the Romans didn't use Vermiculite. I do want to use the best possible conponents, but tring to keep cost down.

It's pretty cool; the Romans seemed to use a type of expanded clay, which is similar to vermiculite in terms material type and insulation. I got permission to crawl around inside a number of the old ovens, and could handle the cooking floor pieces, under oven insulation, what's left of the dome insulation, etc. It wasn't sand.

As other folks have said, sand is not an insulator -- and I agree that insulation is not a place to cut corners.

Enjoy!
James

[jhobbs]

Re: Sand instead of Vermiculite?

I want to thank everyone who has responded to my post, I am impressed with the number of responses. I belong to several different forums and have to say I appriciate the quick and informed response to my post.

Onto the subject at hand, I have read all your posts and finished the e-book, I will take your suggestions and will use the vermiculite and perlite. Every ones responses had me reading some of the other posts and I am really glad I did ask because I am now considering increasing the insulation on the floor and turning the bricks on there side or making the insulated vermiculite floor thicker.

I have decided to use the 36" Tuscan style plans; I like the idea of being able to cook more than just pizza and bread. Would the standard plans on a 36" Tuscan oven retain enough heat to bake a couple batches of bread after an hour or so after a pizza or roast was cooked? (using the 1" blanket and 4" of vermiculite.)

[dmun]

Re: Sand instead of Vermiculite?

I have decided to use the 36" Tuscan style plans; I like the idea of being able to cook more than just pizza and bread. Would the standard plans on a 36" Tuscan oven retain enough heat to bake a couple batches of bread after an hour or so after a pizza or roast was cooked?

Yes, you can bake any kind of thing you would need for home use with the pompeii, including a multi-hour turkey roast. There is a declining temperature curve, so if you were doing multiple batches of bread, you would do the things that bake at a higher temperature first.

[RTflorida]

Re: Sand instead of Vermiculite?

j,
you might want to download all of the e-books. if you are interested in baking bread the Wood Fired Bread e-book is a good starting point.
Several of our members are bread experts (in my opinion) - canuckjim, dutchoven, and Frances come to mind. They have shared alot of their WFO bread experience on the forum, might want to search their posts.

RT

[RTflorida]

Re: Sand instead of Vermiculite?

Almost forgot our fearless leader - James; he is becoming quite an experienced amateur baker along with his wealth of knowledge of WFOs in general.

RT

[asudavew]

Re: Sand instead of Vermiculite?

I think it's a great idea to increase the thickness of the vermiculite layer.
But I would just lay the floor bricks flat and not on their sides... it will take you much longer to get the floor hot and the floor is the hardest part to heat... IMHO

Dave

[wlively]

Re: Sand instead of Vermiculite?

Have got to second Dave's post. The floor take a very long time to heat up. Better to go with a second layer of insulation under the floor (2 boards or 3+" vermiculite and 1 board) than sideways bricks.

[Xabia Jim]

Re: Sand instead of Vermiculite?

Dittos to the advice provided....the floor is often the hardest to get hot so flat bricks and good insulation under it will work for most applications.

If it was a commercial operation or being used for days on end then the bricks on the side would be a good idea.

most of the applications here are for the home baker and the design works well.

I did insulate my hearth after installation but it was a modular oven application. When I built my second oven, I used 6" of perlcrete....you learn more as you go along......