We regularly receive email asking about using hempcrete in the Monolithic Dome or EcoShell. Hempcrete uses natural hemp fibers embedded in a lime binder — usually cement. It can provide some insulation and a little strength, but if used in a Monolithic Dome it actually weakens the dome and reduces its energy efficiency.
It isn’t that strong
Hempcrete is 1/20th as strong as standard residential concrete. Sure, plain concrete with hemp fibers might have a slight increase in tensile strength than concrete alone, but compared to steel (or even basalt) reinforced concrete, there’s no contest.
What about just using hemp fibers for all reinforcement? It will be a disaster. We learned from hard experience that even steel fiber reinforcement will lead to building failures. Hemp isn’t nearly strong enough to handle the reinforcement requirements for a building people are expected to live in. Never use fibers — of any kind — as sole reinforcement for load bearing concrete. It can kill someone.