Hemp Building Australia - Sanctuary Magazine Feature
Hemp Building Australia – is a team focused on hemp in the building industry to create aesthetically pleasing, environmentally-responsible, functional habitats. Sanctuary Magazine Hemp House features walls constructed by Darren Christie (IHAV) & Andrew Luxton (IHANSW).
FAQs about Hemp-constructed walls as Carbon (CO2) Sinks:
Hemp produces more biomass & absorbs a greater quantity of CO2
Hemp has great insulation, thermal and acoustic properties
Construction of Walls -are constructed by setting out the form-work to plan. Post & beam walls are preferable to stud walls as they use less timber & decreases construction time. A typical wall is 300mm thick - recommended by the Building Code of Australia (BCA), Australian Standard HB 195-2002.
Hempcrete is a combination of hemp hurd, binder and some water in a betonniere (pan mixer).
The mix is poured into the form-work & tamped by hand using wooden tools. The firm, manual, manipulation of hempcrete in this way compresses the hemp mix together, helping it to bind & to give a pleasing finish. It is also soft enough to allow millions of air pockets to form within the wall between the hemp hurd. These air pockets act like double-glazing, increasing the insulation properties of the wall & act effectively as thermal mass - absorbing heat during the day/releasing it at night.
The lime-based binder is absorbed into the hurd - when left to cure, lime (CaO) binds with silica (SiO2) within the hurd, creating calcium silicate hydrate (C-S-H). As the calcium silicate crystal grows it connects with other crystals. Calcium silicate crystal within hurd binds with those same crystals found within the binder to form a very strong, calcified structure when dry. After curing is complete, the form-work is removed, the walls left to dry & either left raw (textured) or rendered with a lime and hemp mix with similar properties.
Hemp hurd & binder used by Hemp Building Australia is 100% Australian. While in France Andrew Luxton has been assisting a hemp-builder from Canosmose heritage.
Overseas Building Links
Klara Marosszeky-First HempCrete building in Singapore Singapore Botanic Gardens The CDL Green Gallery celebrates Singapore's greening journey over the last 50 years.