Craft
Light
Around 340 kg/m³, easy to lay by hand.
Cutting
With a band saw, alligator saw, hand saw or circular saw.
Laying
With the matching IsoHemp thin-bed mortar.
Plastering
With vapour-permeable, cement-free lime or clay plaster.
How to work with hemp blocks
Hemp blocks are not load-bearing and are installed in a timber or concrete frame or the Hempro system. Here are the key points for the site; all details are on the Processing page.
First course: on external walls and damp substrates, a damp-proof course goes under the wall, as it must be protected from rising damp.
Temperature: do not lay below 5 °C or above 35 °C. When plastering above 30 °C, briefly dampen the blocks first.
Loads: toilets, washbasins, wall cabinets, radiators and similarly heavy items are fixed to the frame.
Plaster build-up
Dampen the wall before plastering. Inside, approx. 1.5 cm Hessler HP 9L as base coat, outside approx. 2 cm, then Hessler HP 90 as finish coat (approx. 1.5 mm) or equivalent products. Conluto clay plasters can also be used inside.
In renovations, full-surface reinforcing mesh is suggested; in new builds only at key points such as wall-window and wall-door junctions. The plinth must be protected from water.
Internal and external insulation
The hemp blocks are fixed to the existing wall with wall hooks: 3 per m² indoors, 5 per m² outdoors. The existing wall must be structurally sound and carry the weight of the insulation. Observe maximum widths and lengths.
Windows, doors and lintels
Normal-sized windows can be fitted directly to the hemp blocks with a timber frame. For larger windows, the frame is planned to the left and right of the opening. IsoHemp lintels made of hempcrete with a reinforced concrete core are available for openings.
Questions about your site?
Send us your plans and we will help with the build-up and materials.