If you want to insulate stone, rammed earth or brick walls, you can use a mixture of lime and hemp. The thickness of the hempcrete depends on the type of wall and will affect the thermal and acoustic comfort of your home.

Hemp and lime coatings primarily serve to improve the thermal and acoustic insulation of cold stone and paving walls during the winter. This type of cladding eliminates the ‘cold feeling of the walls’ (radiation), while maintaining a hygrometric balance and minimising damage to the thermal inertia.

Field of application

Lime mortar and hemp shavings can be used in new constructions or renovations.

Coarse hemp shavings can be used as a 5–8 cm filler in the first layer, and fine shavings can be used for a 1–2 cm finish.

It is not recommended to apply hemp and lime plaster over cement plaster.

Realising your own project is straightforward. This type of mortar is easy to use.

Characteristics

Depending on the dosage, dry mix densities can range from 500 to 1,000 kg/m³.

Hemp mortar with a dry density of 700 kg/m³ has a thermal conductivity of around 0.12–0.15 W/(m·K).

During preparation, the surface should be made rough so that the plaster can adhere to the substrate. For thicknesses greater than 4 cm, the hemp and lime mortar should be applied in two passes.

Storage

The material should be stored on a level surface, sheltered from the rain and in a well-ventilated area.