Hemp can be used to build and renovate buildings with healthy, local, renewable and sustainable materials. Several products are already available and used, such as hempcrete and hemp insulation. They are ecological alternatives proven since the beginning of time that we rediscover and improve with today’s techniques!
THE QUALITIES OF HEMP
It is the inner part of the stem, the hemp, that is used for construction. One hectare of hemp produces, in addition to seeds and fiber, four to five tons of hemp seeds. With its high cellulose and silica content, hemp combined with lime forms a half-mineral half-plant material. It combines the advantages of wood and concrete without their disadvantages.
- Abundant, affordable and rapidly renewable resource (grows in 3 to 4 months).
- Natural and healthy (without emission of VOCs or other harmful or allergenic products).
- Local product (currently, in Canada, hemp stems are still rarely used and therefore often imported from Europe, but it is very likely to change in a matter of years)
- Breathable: It prevents condensation and allows air exchange.
- Naturally rot resistant.
- Very light.
- Carbon well, it stores CO2.
- Thermal mass, it stores heat then irradiates it.
- Very good thermal and acoustic insulation.
- Fire resistant.
- Resistant to rodents and insects.
AMONG THE PRODUCTS ALREADY AVAILABLE
- Hemp concrete is a mixture of hemp (the inside of the shredded stem), lime and sand. Chipped in molds, it allows the creation of a one-piece building, thus avoid thermal joints and bridges. It is seven times lighter than concrete, it can be worked with a concrete mixer and can also be used for floors.
- The concrete blocks are the preformed version of the above mixture. Lightweight and standardized in size, they are easy to assemble with mortar joints.
- Insulation panels made out of hemp fibre offer a great alternative to synthetic insulation products such as glass wool or foam. They are available in different thickness, including flooring underlay.
- The bulk insulation for filling is made of hemp stabilized with lime. It is a natural and durable alternative to any insulation type “filling” (ex: roof insulation or others).
- Finishing coatings are made of a mixture of hemp and lime generally applied by trowel. They are at the same time aesthetic, insulating and soundproofing.