The renewable and sustainable wall made of hemp and lime I've seen a test of this incredible material which was under extreme heat for 4 hours at 650c (1202°F) all without combustion,

The renewable and sustainable wall made of hemp and lime

I've seen a test of this incredible material which was under extreme heat for 4 hours at 650c (1202°F) all without combustion, leaving the other side of the wall almost completely cold and unaffected

What is the secret ingredient missing from "Roman" concrete being so durable and lasting for 1000 years? Hemp.