Advantages of thermal insulation with hemp insulation

Choosing natural materials for the home is an increasingly common practice. People have realised that they can protect their health by using natural products with properties as similar as possible to those of materials used in the past for building, insulating and finishing their homes. As far as thermal insulation is concerned, natural fibre materials are increasingly preferred. They use wool, wood fibre, jute, cork and hemp. Hemp insulation performs similarly to conventional insulation made with top materials. The differentiating factor is the natural component which is a valuable bonus: a healthy environment, both during installation and operation.

What is hemp

Hemp is an industrial plant cultivated since ancient times. It grows very fast and can reach 4 m in only 100 days. Strong, woody fibres are obtained from its stalk. Through specific processes and techniques they are softened and can be used for weaving. In the past, their use in the manufacture of clothes or blankets was common practice.

With the advent of synthetic fibres hemp fell into a shadow, like flax and wool, but their potential was not ignored and they began to be used in other areas - flax to make the oil used to finish the wood, andwool for insulating houses.

Hemp has perhaps the greatest potential. It is not only used for insulation products but also for building materials. Hemp bolts are used in construction with very good strengths. Such bolts have also been produced in Romania (by Liviu Butnarua friend of our magazine). Mr. Butnaru tested the strength of the bolts at the Institute of Construction in Iasi, obtaining very good results.

Advantages of using hemp insulation

Hemp insulation has the advantage that is environmentally friendly, natural and has a positive carbon dioxide balance. What does this mean? It means that the plant consumes more carbon dioxide during the growing season than is released into the atmosphere during the insulation production process. For a synthetic product such as glass wool or polystyrene this balance is negative.

Hemp is chosen because very efficient thermal insulation. Thermal conductivity is o.038 W/mK, heat storage capacity between 1600 and 2300 J/kgK and density between 30 and 42 kg/m³. The values are comparable to those of glass wool or basalt wool.

In addition, using hemp insulation comes with other advantages:

• Does not irritate skin, mucous membranes and lungs. This type of insulation is very suitable for insulating houses where people with allergies, asthma or breathing problems live;
• Contains no hazardous substances. Hemp has large leaves and as it grows they shade the soil so that hardly anything grows around it and so there is no need for herbicides. The fibres obtained are healthy and free of chemicals. Hemp insulation can contain ammonium phosphate or calcium carbonate (soda), natural substances that do not attack the body but greatly increase fire resistance. Boron salts (such as borax, a substance also used as a medicine) can be used against mould;
• Can be used as sound insulation. Hemp fibres are a very good sound insulator because of their ability to change the wavelength of sound waves as they pass through them;
• It has no smell and due to the lack of albumin it is not attacked by moths or cockroaches
• Requalises humidity in the room. Hemp fibres can retain an amount of moisture which they release when the humidity in the room drops very low. It is very suitable for wooden houses because it allows wood to naturally exchange moisture with the environment. Being permeable to water vapour, it maintains a healthy environment by balancing the humidity inside, thus avoiding the problems of condensation and mould.
• It is a recyclable material. If alterations are made or the house is demolished, the hemp insulation can be recovered.

It is considered a very good insulation material, but it cannot be perfect. Because of its water storage capacity, it cannot be used for insulating very damp spaces such as basements. However, with a suitable vapour barrier (a protective sheet) dampness can be kept under control and the cellar or basement can be insulated.

Where it can be used. Types of insulation. Assembly

Hemp insulation can be used for roof insulation, loft insulation, between floors, ceiling and wall insulation, under wooden floors. It can also be used to insulate the facades of wooden or brick houses.

Hemp insulation can be in the form of mattresses with different thicknesses or in the form of on. Mattress pads are firmer, stiffer and allow insulation without thermal bridges where heat can be lost.

For the assembly the boards are cut with a special knife because hemp fibre is "woody". The boards can be ordered directly from the factory or from distributors in the desired dimensions. The dimensions of the mattress (length and width) must be 1-3 cm larger than the place where it will be mounted (between the rafters). The mattress is then pressed into place and does not need to be fixed with clamps, adhesive or other materials. For best results, two layers of insulation can also be fitted. The hemp mattress is then finished by stapling or gluing a moisture protection film over the hemp mattress.

Roll insulation is more flexible and needs fixing. Fixing is usually done with a layer of drywall that is fastened to rafters or studs.

Where to find hemp insulation

In Romania, at Naturalpaint you can find Thermo-Hanf hemp insulationproduced in Germany. I have already told you about them because they have other natural products in their portfolio that can be used for building or renovating your home. About natural oils for finishing floors, pigmented paints or varnishes for outdoors, natural plasters based on clay or lime or jute insulationwool or wood fibres we have spoken on other occasions.

Naturalpaint also has teams that can do the installation, both inside and outside the house. But if you want, you can also do the fitting yourself. The video below shows how simple it is. The important thing is that the dimensions are correctly passed on to be cut so that they can be fitted by forced pressing, thus eliminating the formation of thermal bridges.

If you want to insulate your home and have breathing problems or allergies it's worth considering hemp as a very viable alternative.