A Deep Dive into MEL/ARCH’s Favorite Materials
At MEL/ARCH we are constantly looking for materials, new or old, that align with the sustainable and green design principles that are at the core of our firm. In this new series, we’re excited to share some materials we can’t help but frequently revisit, both for their functional and aesthetic qualities. These materials help achieve our design visions and ideas with a more sustainable and eco-conscious approach.
This week’s focus is on the product, Hempcrete.
Hempcrete, also referred to as hemplime, is an alternative biocomposite material that can take the place of concrete. It is a composite building material made of hemp hurds and a mineral binder, lime. The hemp hurd, or internal wood core of the hemp plant, has a high silica content, allowing it to properly bind well with the lime.
Hempcrete became a fairly popular product in France in 1990’s, with it’s popularity growing annually. Canada has followed France’s lead in using hempcrete, being popular within the regions of Ontario and Quebec. The hemp agricultural crop has high yields making it accessible in relation to the growing popularity of hempcrete. In fact, hemp provides more biomass than any other singular crop. The farming of hemp requires reduced amounts of pesticides and herbicides than other crops, but can require increased amounts of fertilizer. Once cured and dry, the hempcrete composite does not produce any toxins or off-gassing.
Hempcrete is an efficient insulating material, with the R-value ranging from 1.7/in to 3.0/in. While it does not have the structural capacity to support rood loads, it can be cast as hempcrete infill to support three or four times the compressive load of a standard wall stud.
Hempcrete can be installed in two ways, cast-in place or as blocks. Hempcrete is also a very functional building material, being very responsible to the moisture content of the air. It can easily absorb or release water vapor from the air.