OK, so I live in Arizona and most of the time the temps here are not conducive to beer making. Even inside you cant keep the temps below 75 so I decided to build a lagering/fermentation chamber. I didn't want to spend money on this project so I started collecting scrap lumber to build it with. One afternoon I was on Craigslist in the free section and there was an ad for free lumber. Turns out there were tearing down a Halloween haunted house and had huge panels of Styrofoam walls used to make it look like a castle. They also had several sheets of brand new untouched Styrofoam. Paydirt!! So this is dual layered and yes, its kind of cheap looking, but it holds temp great, and for the most part it was free.