Insulation with hemp fiber

Hemp fiber

Isolate the best buildings to reduce heat loss, thereby reducing energy consumption, it is the basis of contemporary design and, if you do it using natural materials such as hemp, the result will be a project of sustainable architecture.

Choosing fiber hemp textiles as raw material for the thermal and acoustic insulation of the building means to resort to a natural material whose use in the building is fairly recent.



The hemp used for this application belongs to the species Cannabis sativa, the cultivation of which is regulated by the Ministerial Circular of the Ministry of Agriculture, Food and Forestry no. 1 prot. 200/2002, which limits the cultivation of this variety for the reduced content of THC, which constitutes the active pharmacological principle of the plant.
The plant grows well in hot climates and needs little water: that is why it fits well in our country and its speed in growth avoids the use of pesticides that are harmful to the health.

Insulate with hemp fiber

The panels or rolls of hemp fiber are realized thanks to the use of the fiber itself, sometimes treated with boron salts to improve the resistance to fire, and a percentage of polyester fiber. The intrinsic characteristics of the material are:

- Very good insulation from the point of view of thermal and acoustic insulation, also with a capacity compared to the double insulation of mineral origin;

- Good hygroscopicity, ie good ability to absorb and release water: thanks to this feature it is able, therefore, to fight the formation of mold in the environments;

- Breathability;

- Resistance to the attack of the insects;

- Recyclability at end of life, with reuse in the paper industry or as fuel.

The only weak points registered concerns a low resistance to compression and to fire, which is why often is treated with boron salts.

Given the above described properties it is perfect to use as a thermal insulator, both in the perimeter walls of the buildings and in the partition walls, and as acoustic insulation, if affixed in false ceilings or floors, with the aim to reduce the noise impact.
It is provided either in rolls or panels and it does not require skilled work for its laying.

Let's see a few products on the market and their technical specifications.

Acoustic insulation in fiber hemp

The company NORDTEX offers several environmentally efficient and innovative solutions for the construction and building insulation; between these different lines of products of wood fiber, sheep wool, cellular glass and fiber hemp.
Specifically Cannatherm 30-50 consists of hemp fiber insulating panels to be applied on external walls and the roof.



It is soft and flexible panels with high insulating property for both the cold and hot; they show an elevated dimensional stability and performance even in the presence of moisture, they are breathable and resistant to mold and parasites. They are recyclable and environmentally friendly products and they are tested and approved according to the European standards.

As regards the technical specifications, they are made with 85% of hemp fiber and 15% polyester; They are available in various thicknesses from 40 to 120 mm, and have a thermal conductivity λD equal to 30 kg/m³, 0.040 W/(m*K).

The hemp fiber panels can be made with the addition of other fibers of natural origin, such as wood or kenaf, other plant species with excellent insulating capacity.

The K.E.F.I. S.p.a., sole supplier company in Italy of natural fibers and kenaf for thermal and acoustic insulation, offers Isolkenaf, kenaf and hemp natural fiber insulation, which is available in rolls of different thickness and as panels with higher density.

Isolkenaf solves all problems of thermal or acoustic insulation, and in case of application on the wall and on the floor in the insulation of roofs, and is ideal for new buildings and renovation projects. Its thermal conductivity is equal to 0.039 W/(m*K).

Hemp fiber insulation and 65% tax deduction

Being the application of thermal and acoustic insulation, such processing is among those eligible for aid to the extent of 65%, as interventions aimed at upgrading the energy efficiency of the building; for deduction it will be necessary to have an asseveration signed by a qualified technician (engineer, architect, surveyor or expert) which must report the estimated value of transmittance of the old casing and the transmittance value of the new one.
It must also be asseverated that this new value meets the threshold value of transmittance in Table 2 of the Ministerial Decree of 26 January 2010.