I have quite a bit of half-inch styrofoam panels laying around here that I have no more use for after I made my forms out of them for my cob oven. I am ready to insulate and am trying to think of ways to use up this material without tossing it out. I was thinking of cutting them up into small hexagonal pieces and tiling them around the oven exterior with some perlcrete. I am thinking each piece would be something like 4" wide to better curve around the oven. I think I have enough of this that with the perlcrete I have, I could probably do two layers.

The R-value on the styrofoam is 3.2. What I see for perlcrete on perlite.org at a 1:6 ratio or so is an R-value of around 1.5. So I figure there would be some gain in insulation by using the styrofoam this way.

Edit: I did some searching for an actual data sheet on the brand of insulation, and it does say the maximum long-term temperature is 167F, so I see that's out.

The R-value on the styrofoam is 3.2. What I see for perlcrete on perlite.org at a 1:6 ratio or so is an R-value of around 1.5. So I figure there would be some gain in insulation by using the styrofoam this way.

Edit: I did some searching for an actual data sheet on the brand of insulation, and it does say the maximum long-term temperature is 167F, so I see that's out.

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