Super Isol vs. vermiculite concrete

[Alan]

The Super Isol insulating board has better compressive strenght than vermiculite concrete and better insulating characteristics as well (see http://www.skamol.com/pdf/1%5Bcalciu...s%5DLetter.pdf and http://www.schundler.com/vermcon.htm), and while it's not cheap it would save a lot of time and would eliminate concerns such as getting both pours done in one day.

Any actual experience comparing the materials?

[james]

I think Alan has it right. The Super Isol costs a little more than the cost of the vermiculite and concrete that it replaces (not a lot), but it counter balances that cost with convenience. If you are paying someone to do that part of the job, I think the labor savings probably makes the two alternatives pretty comparable from a cost perspective.

There are also the intangibles, including the effort of mixing and pouring the vermiculite concrete, two pours in a day, needing a helper, finding vermiculite locally, driving to pick it up, etc.

The good news is that you get to decide what works for you depending on your own circumstances.

James

[CAM]

So how do you finish the top of it. If this sits on the concrete hearth then it is exposed no? Can you tile over it? Also, do you glue it down or just lay it there.?

[james]

You use the Super Isol just for under oven insulation. You never see it after you have installed the oven. You glue it down, and assemble the oven on top of it. The insulfrax wraps around the oven, and the vermiculite goes around that. Basically, the whole oven chamber and floor are wrapped in insulation.

James

[CAM]

I gotcha! I had picured it replacing the entire layer of vermiculite. Makes perfect sense.