Insulation with hemp mortar or concrete

For the past 20 years, PROMPT natural cement has established itself as the suitable and compatible mineral binder for all types of plant-based aggregates, especially hemp shives.

Its low-temperature firing, additive-free production, unique mineralogical composition, and qualities of durability, speed, and vapor permeability make it the ideal binder for the production of bio-based mortars and concretes.

The compatibility of hemp shives and PROMPT natural cement has been evaluated and certified according to the characterization methods of the professional rules of Constructing with Hemp, this professional rule is known in French as "Construire en chanvre" .

 

Solution

Hempcrete is a mixture of hemp shives, a mineral binder, and water. Notably, hemp is a plant that requires no pesticides, minimal water, and promotes soil regeneration. Hempcrete insulation reduces the environmental impacts of buildings while enhancing living comfort within homes. Hempcrete offers several advantages, including thermal and acoustic performance, excellent hygrothermal capacity, good indoor air quality (no emission of VOCs: volatile organic compounds), fire resistance, and 100% recyclability.

It can be used for renovating floors and slabs, insulating walls and roofs, as well as creating interior partitions. These mixtures also allow for the creation of lightweight upper-floor screeds and insulating renders.

 

Technique

Hempcrete is an insulating material available in various forms on the market: precast blocks and panels, sprayed (or shotcrete) and shuttered (or compacted) on site.

The choice of materials and application type will depend on the project's requirements and constraints. PROMPT natural cement has been validated according to the professional rules of Constructing with Hemp "Construire en chanvre" and can be combined with certified "building-grade" hemp shives to produce sprayed or compacted hemp concretes.

In the case of shuttered application, PROMPT natural cement provides optimal rapid setting to reduce project timelines, while also exhibiting its characteristic ochre color aesthetics. The addition of the retarder TEMPO extends the setting time of the natural cement grout, making it suitable for spraying, even in cold weather.

PROMPT natural cement is also the natural binder used in the production of BIOSYS blocks.

Simultaneously, the thermal inertia contributed by hempcrete allows for optimal phase shifting, enabling it to act as a natural air conditioner during summer months.

This feature ensures the construction of bioclimatic houses with very low heating and/or cooling costs. Its excellent vapor permeability is also noteworthy – a vital trait in energy-efficient renovation of old structures (stone, cob, rammed earth, etc.). The rapid setting and hardening of PROMPT natural cement help reduce the construction timeline of hempcrete when shuttered.

Lastly, its adjustable setting time when using the TEMPO retarder (citric acid) provides the necessary workability time for spray application. Hempcrete is not only a technically efficient material but also effectively addresses the environmental challenges of tomorrow's buildings. Hemp shives are derived from hemp stem retting, a sustainable crop with a low environmental impact, characterized by its high carbon storage capacity per hectare (15 tons of CO2 per hectare).

Among its qualities, hemp cultivation stands out for its agronomic characteristics, as it requires minimal inputs, is low-water-consuming, and increases soil water retention capacity.