The duck shelter is in the walkout basement - not heated, but well insulated. The original duckhouse is double-walled, insulated with perlite and vermiculite.
Oh, it is true that some of us run into the least likely scenarios. With me, it's fiberglass insulation. As I wrote, nothing bad about it, I just have seen too much of what can go wrong.
I won't say rolled insulation is bad. But I saw what rolled insulation can get like after a few years, and . . . well . . . it was yucky. Some slid down the wall so it was only in 2/3 of the wall, some got mousy and kinda moldy. I have seen people use sheets of foam for insulation, but if...
I built a double-walled shelter and filled the gap with vermiculite and perlite. I used those because they are minerals and do not burn, and do not mold, and do not gas off. I also put in a three panel clear plastic drop ceiling to further insulate, because there are large gaps covered with...