HEMPCRETE

BUILDING WITH HEMP

When hemp hurd (the woody core of the stem) is mixed with a lime binder and water it petrified into a biocompsite substitute commonly known as Hempcrete. Hempcrete is lightweight cementitious insulating material weighing about a seventh or an eighth of the weight of concrete. Fully cured hempcrete blocks float in a bucket of water.

Hempcrete has significant advantages over concrete. It is breathable, fire resistant and a good insulator, and can be used as a fill around a timber frame, as a finishing plaster, or to build freestanding walls.
The Hemp plant absorbs atmospheric CO2 during the plant growth phase, and again as the material gains strength and matures. (100sq m with 300mm thick walls) will lock up 7.9 tons of CO2 in the walls. Estimated rate of carbon sequestration is 165Kg CO2 capture/m2. Therefore, building with Hempcrete reduces atmospheric CO2.

EXCELLENT THERMAL INSULATION CHARACTERISTICS

Hemp houses show superior thermal properties to the conventional homes: the exterior walls of the conventional homes were 4-6°C warmer than those of the hemp houses, indicating that loss of heat through the conventional brick walls was considerably greater than that through the “Hempcrete’ walls

EXCELLENT ACOUSTIC ISOLATION

Hempcrete has very good acoustic components due to its open structure. Hempcrete has a low propagation rate, a figure of ~900Vson m/s against steel with ~6110 Vson m/s. Hemp concrete is characterised by its high porosity that combines the microscopic pores of its binder and its vegetable particles, and bigger pores between the particles. Thus, its sound absorption is intermediate between the excellent absorption of hemp shiv, and the reflexion of the binder.

Fire Retardant, Termite & Rodent Resistant

Fire tests on a 300mm thick Hempcrete wall gave 73 minutes, for structural adequacy/integrity/insulative capacity. Further tests are being undertaken by the labs of Cesa, St Estier limes in France.

John French, a leading Queensland and international entomologist, has tested Hempcrete in the Northern Territory and Queensland found termite have no effect on the Hempcrete samples.

FIRE RESISTANCE TEST AFTER 4 HOURS

HEMPCRETE OVERVIEW

The material is mixed in mortar mixers for 1-2 minutes and stuffed by hand into the wall cavities. The wall is slip-formed with temporary wooden or plastic “shuttering” forming the inner/outer surface forms. The material is lightweight and can be moved easily about the site in tubs and passed up bucket-brigade fashion to workers filling the cavities. Site clean-up is easy. Simply till it into the soil.

The material is finished on the outside with a hard render coating about 20mm thick to protect it with a final colored topcoat finish added. The end result appears like any stucco finished building. The inside can be left natural or finished with lime plaster for a traditional look.

Hempcrete was discovered in a bridge abutment in France built in the 6th century. Since its rediscovery it has seen growing use in Europe. Industrial hemp is grown by certified commercial growers so the crop can be certified to be very low in THC. Hemp is not psychoactive. Given it has survived 14 centuries, people expect Hempcrete buildings will have a long life.

Hemp itself is a beneficial crop requiring no fertilizer, weed killer, pesticide or fungicide. It grows so thickly that weeds cannot grow. Farmers grow it in rotation with other crops such as barley or rye. The crop following the hemp requires no weed killer because the hemp has driven weeds out. The hemp seed is harvested as a nutritious food supplement rich in Omega-3 oil, amino acids, protein and fiber. It is considered a “super food”. The outer fibers are used for cloth usually as a blend with 45% cotton. The woody inner core is chopped to uniform size for our use. It has been traditionally used as animal bedding.

INTRODUCTION TO TRADICAL®

Tradical® construction materials are developed products of the Lhoist Group based on high purity manufactured lime materials. The Lhoist Group is an international business focused on the supply of high purity lime products to many industries including the construction industry.

Tradical® Hempcrete is a unique, highly sustainable construction product for the creation of insulating walls as well as insulation layers for roofs. 

Tradical® Hempcrete is a blend of specially prepared hemp shiv and a special lime based binder Tradical®. Together these products form a bio-composite building material that can be used both for the creation of buildings that have excellent thermal and acoustic properties as well as creating a healthy living and working environment.

Additionally, Tradical® Hempcrete has the ability to make an impact on the future of sustainable building. Helping to reverse the damaging effects of greenhouse gases, Tradical® Hempcrete locks up approximately 110kg of CO2 per m3 of wall and provides one of the best value materials for low impact, sustainable and commercially viable construction.

Produced mainly from renewable sources, Tradical® Hempcrete is mixed on site for fast track construction and delivers high levels of insulation, air-tightness and vapour permeability.

PROPERTIES

Benefits And Capabilities

Combining patented formulations of air-lime based binders with the chopped core of the industrial hemp plant stem, delivers a suite of new building products. These Tradical® Hemp Lime products have excellent performance characteristics for durable, healthy, sustainable and ecologically sound buildings.

Tradical® Hemp Lime products deliver excellent application, durability and aesthetic performance characteristics combined with sustainability, economic, comfort and health qualities that architects, developers, contractors and customers will value.

  • Design
  • Application
  • Durability
  • Aesthetics
  • Sustainability
  • Economic
  • Comfort & Health
  • Carbon Balance

Tradical® Products

Tradical®: these ready-to-use pre-formulated binders combine air lime and hydraulic binders so that you get the best of both for your projects. To be used in brickwork and blockwork, rendering & plastering.

Tradical® is a product line of different air lime-based pre-formulated binders to meet all needs in terms of building masonry, rendering and plastering in the renovation and new build market segments.

Tradical® incorporates in one mixed product all necessary ingredients to make high-quality/high performance air lime mortars compatible with all kinds of wall structures.

Tradical® brings all the necessary performances for a successful masonry work:

Scroll to Top