Loose-fill
hemp-lime
Loose-fill hemp-lime is a biobased insulation, used in particular to fill floors, lofts or cavities. Light and breathable, it contributes to thermal insulation and to natural moisture regulation.
What is loose-fill hemp-lime?
Loose-fill hemp-lime is a pre-dried biobased insulation made of hemp shiv, from the woody core of the hemp stem, and a natural lime binder. The shiv acts as an airy plant-based aggregate, while the lime provides cohesion and fixes atmospheric carbon dioxide during carbonation. The mix is installed dry, without a vapour control layer.
This composition combines lightweight thermal insulation with natural moisture regulation. The material remains vapour-open and buffers climatic variations across the wall. Its lightness and the absence of additives make it suitable for new-build projects as well as for the renovation of older buildings.
The loose fill is therefore used for floor insulation on slabs, for filling lofts and roofs, and for filling wall cavities. Depending on the use, a thin layer is enough for acoustics, and a thicker one for thermal performance.
It is manufactured in Belgium, by Exie in East Flanders, from hemp shiv co-produced locally by the hemp supply chain. The binder is a natural lime. At end of life, the loose fill can be ground and reused as a raw material, or composted.
Installation & uses
Installation is dry, by hand spreading or mechanical spraying, without a vapour control layer. On floors, the loose fill is poured in two layers and lightly compacted, with an activator added to speed up carbonation. A screed can then be poured the same day.
In lofts and roofs, the loose fill is blown between the joists or into the cavities. For wall filling, spraying covers large areas in a short time. In all three cases, the material is kept away from liquid water while it carbonates.
The mix then hardens over the months, in contact with atmospheric carbon dioxide, with no further intervention. The producer supplies separate installation guides for floors and for walls, with the associated thicknesses and timings.
At end of life, the material can be removed from the substrate and ground, then sent to a composting route or reused as fill on a new site.
About the producer
Exie is a Belgian producer of hemp-lime products for construction and renovation, based in East Flanders under the motto Experts in Healthy Houses. The company develops two complementary formulations, CaNaDry as a dry loose fill and CaNaCrete as a wet mix, from hemp shiv co-produced locally by the hemp supply chain.
It supports specifiers and contractors with detailed installation guides and technical support ahead of work on site, and offers mechanical spraying for large areas.
Technical performance
EN 12667:2001 (λ) · EN 13501-1:2018 (fire) · EN ISO 10140-2:2010 + EN ISO 717-1:2013 (acoustics) · EN 826:2013 (compression) · DIN EN 1602:2013-05 (density) · EN 15804+A2 (embodied carbon)
FAQ
Is loose-fill hemp-lime loadbearing?
No. The loose fill is non-structural and is always placed on loadbearing joists or a loadbearing slab. Its compressive strength is 426 kPa at 10% deformation, according to EN 826.
What is its embodied carbon?
−86 kg CO₂ per m³, a negative balance: hemp sequesters carbon, and lime fixes it during carbonation. Calculated according to EN 15804+A2, technical data sheet dated July 2025.
What thickness should be chosen?
The product is delivered loose, in 80-litre bags or in big bags · one big bag covers 8 m² at a thickness of 15 cm. The declared conductivity is 0.054 W/m·K, and 0.060 as the design value, according to EN 12667.
What happens to it at end of life?
It can be ground and reused as a raw material, or composted. The lime continues to carbonate throughout the life of the building.
Alongside
Same layer, same use · three materials to compare.
