Once we speak about self supporting structures of cellular glass, which are implicit thermally insulated, the next question raises: what should be the maximum height of such a structure under earth’s gravity?

I estimated this for a cellular glass with 2000 and 1000 kPa compressive strength by calculating the stress under the weight of a cellular glass tower and compared this with other materials. We use the short time compressive strength (or creep stress for wood and steel) and as a consequence, such a high tower is not stable on the long term. However, in the case of pg900 and pg2000, a safety factor = 3 is on the safe side to remain under sub critical crack growth.

The PG900 is commercial available material from GLAPOR, as is the Ytong C2/350. The other materials are standards available at many suppliers. We see that other materials than cellular glass are not necessarily much more self supporting due to their higher density. Wood, developed by nature is very stable in the strongest direction.

Self supporting structures in cellular glass of about 400m height are stable. If we reduce the height to typical home heights, a lot of strength is available to hang the inside structure if a shape is used where only compressive stress is present by using an intelligent curve like a catenary.