"Where to get "Ytong Building Blocks" in North America?" Topic

I ran across this article link over on Armorama. The author of the piece mentions intriguing possible uses the author suggests for something called "Ytong Building Blocks." They appear to be light, easily worked with, but durable and cheap. All in all, a scratch builders dream. From what I can gather, they're a form of building material available readily and cheaply in Europe, but I cannot find any US source for them.

Does anyone know if they're available in small quantities in the US?

This is what they look like in their raw form:
link

This is what can be achieved using them as a modeling material:

Aerated Autoclaved Concrete Blocks

There are a few mfr in USA but I do not know about small retail sales.
Ytong folded up/went under in the USA--poor quality standards to keep up with strict building codes.

I can't remember who sold it, but there used to be a vendor here who sold Rigid High Density Urethane Foam Boards. These are the same as what sign companies use to make carved signs. Lighter and easier to work with. Would easily do what you are looking to do.

Now it sounds to me that "Ytong" is just refractory brick or Fire Brick. As seen here:
link
hitempincusa.com/offers.asp
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link

This stuff I have worked with in jewelry kilns and other high temperature type ovens. It is not very strong and will crush or crack very easily. That said, if you where to coat it (really soak it) with acrylic media or PVA it might be quite strong in the end.

The Urethane carving foam is "Balsa-Foam". Here are some alternative sources as well:
link