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Hemp-based insulation moves mainstream

Stephen Cousins

HemKor range is ‘largely made from hemp’ to cut embodied carbon, although products are not a direct replacement for all non-bio insulation materials

Thermo hanf product.
Thermo hanf product.

Three new hemp-based insulation products have been launched by Kingspan in a step that starts to bring hemp into the mainstream. Hemp is a crop recognised for its high levels of carbon sequestration, and with a minimum of 80% bio-based material overall.

Currently only available in The Netherlands, Germany and Belgium, the products Jute Blend, Pure and Padding were developed at the manufacturer’s IKON innovation centre in Ireland.

Kingspan has suffered drop in trust in the UK after an employee admitted to the Grenfell Tower Inquiry in 2017 it had 'almost kept secret' fire tests on the insulation product later installed at Grenfell Tower. Kingspan later condemned these actions. 

Jute Blend and Pure meet the European standard EN 16785-1:2015 used to validate the amount of biomass in bio-based products, and according to a spokesperson for the Kingspan. Environmental Product Declaration (EPD) certificates for HemKor products are in development and should be available in 2024.

Jute Blend combines hemp with recycled jute bags, it has a declared bio-based content of at least 80% and a thermal performance of 0.040 W/mK. Pure has a bio-based content of over 95% and a thermal performance of 0.043 W/mK. Padding has a bio-based content of 100%, but details of its bio-based content and thermal performance were not made available.

When asked the percentage of hemp in each product, the spokesperson said: ‘The reason we mention “largely made of hemp” is because not all products in the range contain only hemp. For instance, Jute Blend contains Jute, which is also a bio-based material. Furthermore, that product also includes recycled PET as a binder and soda to ensure the desired reaction to fire.’ 

Hemp is a circulation crop that takes just four to five months to mature. Is rapid growth, relative height (up to 5m) and deep roots make it effective at storing carbon. HemKor products are manufactured in Nördlingen, Germany with the hemp grown in Europe, mainly in The Netherlands and Romania.

Thermo hanf production.
Thermo hanf production.

The range is suitable for use ‘in timber and steel frame walls, pitched roof, partition walls [but] would not be a direct replacement for all other non-bio insulation materials,’ said the spokesperson, who added that the flexible material ‘lends itself well to being fitted around penetrations and objects such as electricity conduits and pipes’.

The spokesperson said that Kingspan does not plan to move all its products to bio-based materials as ‘we don’t believe that is what the built environment requires. We believe that architects and specifiers need a full spectrum of insulation materials to meet the complex and differing performance requirements of today’s built environment.’

The new product range aligns with Kingspan’s 10-year sustainability programme, Planet Passionate, which aims to reduce manufacturing carbon (CO2e) emissions to as close to zero as technically possible, and halve carbon intensity in its primary supply chain. The spokesperson added that IKON focuses on reducing the embodied carbon of existing products and introducing new products that are naturally very low in embodied carbon. 

The benefits of using hemp in construction are gaining increasing recognition. A researcher at the University of Cambridge recently said that hemp is more effective than trees at sequestering carbon and able to capture atmospheric carbon twice as effectively as forests.

Designers pushing awareness of what can be achieved with hemp and other sustainable, bio-based materials, include Practice Architecture and Material Cultures, whose Flat House is made of the material.



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