What is Hempcrete?

Hempcrete, like adobe cob, is a natural geopolymer building material. The a combination of hemp hurd and lime, creates a lightweight fibre-based concrete.

Previously a leftover product of the industrial hemp industry, “hurd” or “shiv” is the crushed wooden core of the hemp plant. It’s what remains after the oils and fibres are harvested for everyday products.

A sedimentary rock formed from millions of years of ocean life, lime is a crystalline mineral used all over the world in masonry and concrete products, its reactive chemical nature makes it an ideal binder for hempcrete.

The covalent (polarized) nature of water is essential in the creation of hempcrete. While acting as the initial binder, water dissolves the lime into slurry being the key to the re-crystallization of the lime and its function in hempcrete.

Once blended, hempcrete has approximately a 20min working time as it starts to “cure” or solidify; during which it can be cast a number of ways. This new product, which proves greater than the sum of its parts, results in a safer, healthier home that saves energy.

Finished hempcrete gets stronger over time, ultimately “petrifying“ or “fossilizing” into a monolithic stone structure that will last hundreds, if not thousands, of years. Theoretically your grandchildren’s grandchildren will enjoy the castle we’ve created.