What are HCB Hempcrete Blocks?
HCB Hempcrete Blocks are a non-loadbearing, thermal block for use around a load-bearing frame, or applied to existing solid walls. Finishes for HCB blocks include lime render or timber or masonry cladding. HCB provides a vapour open, insulating thermal envelope.
HCB Hempcrete Blocks are made by combining the woody stem of the industrial hemp plant with a lime binder. The blocks are a low embodied carbon alternative to conventional insulated walling systems and are supplied by UK Hempcrete and manufactured by Equilibrium in Italy. Currently the blocks are imported, with plans to begin production in the UK as soon as the market will support this. HCB blocks have been selected as ASBP’s Product of the Month because evidence suggests that they are a low embodied energy construction material with a thermal and hygroscopic performance which produces comfortable, healthy energy efficient buildings.
The pre-cast HCB block makes hempcrete available to all builders.
What are the benefits?
The table below outlines the performance of the LEED certified blocks, including their acoustic performance, thermal conductivity and specific heat capacity. The combination of hemp and lime (the only constituents) is naturally fire- pest- and rot-resistant, so no additional chemical treatment is needed, meaning no VOCs or other harmful chemicals in the final product. HCB blocks are hygroscopic; passively regulating internal humidity to avoid condensation and damp, and promoting the comfort and health of building occupants.
Performance characteristics of HCB Hempcrete Blocks
U-values of 0.23 W/m2K for the 300 mm block, and 0.17 W/m2K for the 400 mm block, mean HCB block walls meet part L with ease.
The pre-dried blocks are laid in a thin lime mortar bed and measure 20cm high x 50cm long. A range of thicknesses (see table above) means they provide a flexible element within the building design. The pre-cast block makes hempcrete available to all builders, who may not have the specialist knowledge required when hempcrete is wet-cast and dried on site.
HCB Blocks (prior to rendering) in William’s Den; a new-build children’s play barn currently under construction in East Yorkshire, designed by Native Architects of York.
With a long pedigree as a specialist hempcrete and natural building contractor, UK Hempcrete now supplies hemp building materials, including the HCB block, hemp and binder materials for cast-on-site hempcrete, and all associated materials.
Phone: +44 (0)1629 343 143