alternative insulation???

[danqui]

what can i use, under the ovenfloor, heard of sand...
and for the covering, adobe with straw, cowshit, ...??

[Jed]

Originally Posted by danqui

what can i use, under the ovenfloor, heard of sand...
and for the covering, adobe with straw, cowshit, ...??

Danqui,

Sand is not an insulator - adobe with straw is usually made with high amounts of clay, which is not an insulator. Cow excrement is fertilizer, not insulation.

Insulation under the floor is critical if you want the oven to perform. Without insulation you won't get the oven floor temperature to stay hot, making it very tough to cook anything...

Use a good masonry panel insulation - one that can tollerate the 1,000 F temperature and the weight of the oven. Or use perlite or vermiculite - (mixed with Portland cement per the Pompeii oven construction instructions) either material is commonly available from masonry supply or agricultural supply stores.

If you skimp on the insulation you will end up with an oven that doesn't function well, so take the time to get this part right!

JED

[danqui]

so what did they use some 200 years ago for insulation???
i,m living in the brazilian amazon, so i,m not sure if i find that kind of insulation here, ...

[dmun]

What they used 200 years ago, as well as 2000 years ago in Italy, was volcanic pumice. Works as a pretty good substitute for vermiculite, used the same way. I wouldn't use anything organic, like straw or cowpatties: at best it would char and stink the place up, at worst it might catch fire when it heats up. Also you want rigidity under your oven, sagging something this heavy and rigid is a prescription for disaster.

[james]

I've also heard the old fashioned product called "Expanded Clay" -- argille espanso.

James

[karl]

Use porous concrete blocks. Simple, easy, no-mess solution. Add some 1/3 insulation thickness compared to vermiculite/perlite and you get approx. equivalent insulating effect.

karl

[dmun]

Use porous concrete blocks.

Hebel or AAC blocks are a fairly obscure item, at least here in the states. I don't know if he could find them in South America.

[karl]

Hebel or AAC blocks are a fairly obscure item, at least here in the states

That's a pity. They are in fact very environmental friendly building materials compared to regular concrete and other construction materials. I hope they are available to him (in particular if his other choice is cow-shit!).

Regards from Karl

[JoeDuarte]

[You can use sand (areia in portuguese, you must have lots in the amazonia

[danqui]

heard that sand is not so good, ...
i will check the local market, and see what is available.
will tell you my solution

how hot does it get under the oven flor??