Quote Originally Posted by Gadgeteer View Post
How about styrocrete?
I worked on a building that was constructed somewhere between 1950-1970. It was an electrical house for a big mine hoist. It was the site of a natural disaster and part of our project was replacing the roof. Quite a large building by e-house standards, about 50 x 200. The roof was constructed out of pre-cast highly aerated panels. I think it might have been air-crete, or at least something similar. Very interesting material. I think it may have had some aluminum-oxide component, but it was largely concrete and air. It felt like aged styrofoam that had been left in the sun too long. You could cut it with your fingernails. It looks much lighter in color than concrete, gray or almost white and very brittle and extremely lightweight. Anyway apparently it had a halfway decent r-value. I forget now. Interesting product. But I don't think it could be poured, and it wasn't exactly structural.

I can't claim to have used or know much about styrocrete, but I thought that was a non-load bearing external application like stucco. I might be wrong about that though. I've used cement board many times. It's almost like drywall or something, but it's constructed out of cement and little styrofoam balls. That's an interesting product too. Those sheets like to snap in half though. Bit of a pain to be honest.