Hemp

An annual herbaceous plant belonging to the Moraceae family, subfamily Cannaboideae. The term hemp refers both the plant, Cannabis sativa, and the textile fiber derived from it.

Hemp has accompanied human history since the dawn of civilization. As one of the fastest-growing plants on Earth and valuable, versatile resource, this plant has provided food, fibers for textiles, armor, ropes and much more right up to the present day.
Today, hemp is used in a wide range of products, from biofuels to construction materials to everyday accessories, always with a focus on environmental care and sustainability.

Features:

Sustainability
Resistance
Breathability and hygrothermal regulation
Thermic insulation
Acoustic insulation

Applications:

Panels (made from hemp fiber and fixative components) and boards (made from hemp shiv and natural resins)
Mortars and plasters
Compounds for insulating layers
Hemp-lime plasters
Paints and coatings

Breathability (μ)

≤ 2

Ability of a material to be passed through by water vapor
Protect yourself from condensation and mold: the lower its value, the greater your ability to dispose of internal moisture
Thermal Conductivity (λ)

0,038-0,040 W/mK

Indicates a material ability to conduct heat.
To protect against the cold: lower is the value, the better the insulation
Specific Heat Capacity (Cp)

1.700 J/KgK

Indicates the amount of heat required to raise the temperature of a substance by one degree
To protect against heat: the higher the value, the more slowly heat is absorbed
Density (ρ)

100 Kg/m3

How is the mass of a material distributed in the space it occupies
To prevent against heat: the higher the value, the greater the resistance to heat

Hemp, or industrial hemp, is a plant belonging to the botanical class of Cannabis sativa cultivars grown specifically for industrial and food-related purpose. Although both cannabis and hemp are varieties of Cannabis sativa and contain the psychoactive compound tetrahydrocannabinol (THC), they are distinct groups of cultivars, with different chemical compositions and uses: particularly hemp typically much lower concentrations of THC compared to cannabis. Hemp is cultivated in temperate zones as an annual plant and can grow up to five meters tall.

Fibers are extracted from the stalks through several processes, including retting, drying, crushing, and shaking which separates the fiber from the woody core of the stem.

Sustainability

Hemp is more sustainable than traditional construction methods: with lower energy costs and reduced air pollution. His cultivation offers many benefits, such as weed suppression, erosion control, soil remediation and the removal of toxic substances and heavy metals. Hemps requires little water and no pesticides to grow; practically no waste is produced during the industrial hemp processing, it is recyclable, non-toxic and biodegradable.

Resistance

Hemp fiber is strength, durable and is a good protector against pests. If mixed with lime, it also becomes fire-resistant.

Breathability and hygrothermal regulation

Hemp’s natural properties make it mold-resistance and its porous nature (specially of shiv) makes construction materials made from it highly breathable.

Additionally, hemp can absorb and release moisture without degrading.

By the point of view of thermal insulation, it absorbs twice as much heat as based-minerals insulators and promotes air circulation, improving indoor comfort.

Acoustic insulation

Hemp also acts as an acoustic insulator, weakening sound waves carried through it by the air.

Applications

In sustainable construction, both hemp’s fiber and, more commonly, hemp shiv are used. Thanks to its higher percentage of air cavities, the shiv provides construction materials high breathability, as well as moisture absorbing and release properties. Hemp is used in the following applications:

Hemp-Lime Blocks

Hemp is often mixed with lime, sand or pozzolana (used as binders instead of cement), to create what is known as hemp-lime.

In 2022, hemp-lime was accepted by the International Code Council as a building material, along with standardized usage methods. It is available both as on-site made blocks and as commercially prepared products similar to traditional bricks.

Panels (from hemp’s fiber and fixative components) and boards (from hemp shiv and natural resins)

They offer excellent thermal and acoustic insulation, breathability and moisture regulation and they are used in external insulation systems, wall insulation, flooring and roofing.

Mortars and plasters:

Mixtures of hemps shiv, lime and water used to create mortars and plasters on-site, ideal for thermal ad acoustic insulation and moisture regulation. Mixtures brought directly to the construction site and packaged.

Compounds for Insulating Layers

Aggregates made from hemp, lime and water, used to fill cavities or spread across surfaces. Not suitable for load-bearing structures, but excellent as insulating materials.

Hemp-lime plasters

Used to coat surfaces, providing protection, high breathability and thermal-acoustic insulation.

Paints and coatings:

Products for painting interior and exterior walls and ceilings, offering protection against molds and fungi and ensuring high breathability.

Explore other materials

Hemp

Features:

Applications:

Sustainability

Resistance

Breathability and hygrothermal regulation

Acoustic insulation

Applications

Explore other materials

Cellulose

Clay

Common reed

Straw