Homemade Insulation (styrofoam pellets and cement?)

[jackmyhre]

So I have finished constructing the dome of my pizza oven but have not put any insulation on it. I am in Burundi so it is not possible to buy any sort of blankets or wool therefore I am trying to make my own insulation. would it work to crush up styrofoam and mix it with a cement/firebrick dust mixture and put that on the outside? I have large boards of styrofoam that were used to cushion material in a container that was shipped over. my thinking is that the styrofoam would help to insulate and if it burned up in the heat it would leave air gaps that could serve the same purpose. I don't really know what high heat would do to it and am interested if anyone else has worked with it. Or if anyone has other ideas for insulating with few materials available?

[wotavidone]

So I have finished constructing the dome of my pizza oven but have not put any insulation on it. I am in Burundi so it is not possible to buy any sort of blankets or wool therefore I am trying to make my own insulation. would it work to crush up styrofoam and mix it with a cement/firebrick dust mixture and put that on the outside? I have large boards of styrofoam that were used to cushion material in a container that was shipped over. my thinking is that the styrofoam would help to insulate and if it burned up in the heat it would leave air gaps that could serve the same purpose. I don't really know what high heat would do to it and am interested if anyone else has worked with it. Or if anyone has other ideas for insulating with few materials available?

I say no, old mate. In fact, I say no, no, no.
Have you ever seen anyone throw a piece of styrofoam in a fire place? It sorta melts into a sticky mess before it catches fire, and the stink is disgraceful. The odour takes forever to go away. With your oven clad in styrofoam cement, with the potential for the foam to melt but possibly no access for air to assist the burn, I can imagine the smell of molten plastic hanging around for years.
I made styrofoam once. The expanding agent to make the styrene polymer into a rigid foam was hexane. Often benzene these days. i.e. I can even imagine your oven blowing up.

I like your thinking in general though. You can try chopped straw in clay. The straw should eventually burn out leaving air pockets. But without the terrible fumes from styrofoam.
If you can get pumice or scoria you can try a lean pumice and cement mix. Just enough cement paste to stick the pumice together.
A quick internet search indicates that your neighbours in Tanzania have these two rocks. If you can get vermiculite, perlite, or very coarse saw dust from the same sort of timber you'd be prepared use to cook your food, these can all be used to make an insulating concrete.