Lately we've been talking a lot about the green building movement, and one area that deserves more attention is concrete and its alternatives. It's such a ubiquitous material that you hardly ever notice when structures and road ways are made out of it, but concrete's production and use have serious consequences for the natural environment and public health.
The first problem is that making concrete requires a great deal of energy. Cement, a mixture of clay and limestone that serves as a binding agent for the water and aggregate (stone) compounds found in concrete, needs to be ground into a powder, then heated to a high temperature that releases CO2 into the atmosphere. This process gives conventional concrete a high carbon footprint.
Enter hempcrete, a building material that uses the silica-heavy shiv, or core, of the hemp plant as part of the binding mixture that makes up cement. The material achieves a carbon-negative status because more carbon dioxide is consumed by the plant while it grows than is emitted during the production process.
Hempcrete can be used in the same way as concrete. Thought it lacks some of the strength of conventional cement alternative, it is still perfectly safe to be used for homes and smaller buildings. It's also a great insulator, helping you save energy, fireproof, waterproof and it's resistant to mold. Some manufacturers even claim that it's recyclable.
The main obstacle to wider use of this material is that industrial hemp production is illegal in the U.S., due to marijuana laws. But hempcrete can be procured from abroad, and new producers are cropping up everywhere, so it's bound to become more accessible over time.