by Marc Montgomery: Imagine building a house from material that was a carbon sink, highly insulating, fire resitant, insect proof and yet costs almost the same as standard cement block materials.
While cement blocks are a still by far a key construction material in many applications, a relatively new product may slowly take over.
It’s called “hempcrete” made from a mixture of hemp fibre and a lime-based binder.
Hemp has long been vilified as a close cousin of marijuana, the main difference being that hemp/cannabis has virtually none of the psycho active ingredient of the marijuana/cannabis plants.
With the legalisation of marijuana/cannabis in Canada, some U.S states, and elsewhere in the world, some of the stigma and restrictions around growing and using hemp in a wide variety of useful applications have faded.
This has led to growing experimentation of hemp being employed in a variety of ways such as in the making of building materials. Several companies in a number of countries have begun producing variations on ‘hempcrete”.
However, a Calgary company has come up with an interesting innovation.
By working with a Canadian company that creates injection moulded auto parts they have created a form of cones over which the blocks of compressed hemp are moulded.
These leaves the squared tops of the cones projecting out the top resulting in a finished product that resembles children’s snapt together toy building blocks.
In addition to the other advantages of the hempcrete, the similarity to the toy blocks makes construction accurate, faster, and simpler. They can also be cut to shape using ordinary power or hand tools.
The drawback to the hempcrete blocks is that they cannot be used below grade.
The blocks have been tested in different climates from the south-east U.S coast, to the middle of the prairies, to Alaska, with claimed good performance in all of them.