Bob hat geschrieben:Thanks jimmy! I like ytong nests because they retain moisture well. However I heard ytong is rare in this country
YTong is basically just aerated concrete. In the UK it is not called YTong (which is more like a brand/make in a way), it's just "Aerated Concrete", with 1 common/well known manufacturer/brand being "Celcon" (and so sometimes people just call them "Celcon blocks").
In the US, I'd imagine any major DIY/hardware shop (like B&Q... no idea if that's in the US too or not but I'm sure you have plenty of equivalents), or builder merchants, would sell some form of "aerated concrete", just pop in and ask. Check it out yourself - see how soft it is by seeing if you can dig your fingernail in to it a bit by pushing to check it's going to be ok. It's a very common building material all over the world, and the USA is no exception!