HEMP BUILDING MATERIALS

Hemp Building Materials
Hemp can be made into any building material, including fiberboard, roofing, flooring, wallboard, caulking, cement, paint, paneling, particleboard, plaster, plywood, reinforced concrete, insulation, insulation panels, spray on insulation, concrete pipes, bricks, and biodegradable plastic composites which are tougher than steel.

Foundations can be made out of hemp hurds, a processed based on ancient technology adapted for modern use. To do this, one sets up a plywood frame (preferably hemp plywood) to fill with a mixture of hemp hurd (wood chip-like substance that bonds to itself) combined with lime, sand, plaster, some cement, and enough water to dampen, and let the mixture set for half a day.

Hemp foundation walls are 7 times stronger than concrete foundations, half as light, and three times as elastic, which means that these building will bend, but not break. Because of their superior strength and flexibility, hemp foundations are resistant to stress-induced cracking and breaking. Even earthquakes and other natural disaster cannot break or crack these structures.

These foundations are amazing because, after they set, they continue to get harder and stronger everyday until they fossilize, as is testament by a 6th century hemp-reinforced bridge in France. It is not until thousand of years later that these foundations first start to deteriorate.
Hemp foundation homes and buildings are self-insulated, including thermal and sound insulation, resistant to rotting, rodents, insects, and they are fire proof, waterproof, weather resistant, and the walls breath so the rooms do not get stuffy. Hemp homes stay warm in the winter, and cool in the summer.
Hemp hurds can be processed in existing wood mills without major changes to the equipment.

If hemp were legal in the United States, it would be the cheapest source of raw material for concrete-like foundations. Hemp-foundation homes are ecologically appropriate because they are inexpensive, and can be prepared on site using only a cement mixer, and the material would be cheap and abundant.

Hemp building material could allow us to replace the need for wood, bricks, and fiberglass insulation.

Foundation floors can be made in much the same way as the foundation. Hemp resists seepage, and so hemp cement is applicable for pouring onto a soil base to make a foundation floor. The floor insulation hardens into a solid mass that will not shift under pressure.
A German company produces a product call Mehabit, a hemp-hurd substance covered with coal-based bitumen, which is sticky, and when leveled out on a hemp cement floor, will dry to form a thermally and phonetically insulated floor.

Washington State University has produced hemp fiberboard that is lighter, twice as strong, and three times as elastic as wood fiberboard, plus it has sound proofing and pressure isolative characteristics absent from wood fiberboard. These composites are also resistant to pests, moisture, and funguses.

The process involves chipping the hemp stalk, bonding it together with resins and glues, and clamping it down into molds under high pressure until it hardens.

Concrete pipes can be made out of hemp fiber that cost 1/3 that of polypropylene. These pipes have greater flexibility, greater elasticity, and are resistant to cracking.

Stones can also be made out of hemp by wetting the stalks cellulose, and forming it into a hard black rock which can be cut, drilled, cast, carved, or formed into any shape.

Hemp can also be made into compressed door panel and dashboards. Carmakers such as Ford, GM, Chrysler, Saturn, BMW, and Mercedes are currently using hemp composite door panels, trunks, head liners, etc.

In 1941 Henry Ford made a car out of hemp and other composites and bio-plastics that were more resistant to blows from a sledge hammer than other steel cars were.

These composites are less expensive than dangerous fiberglass counterparts. Hemp fibeglas replacements would only cost $10 to $15 a kilo. These hemp composites could replace carbon and glass fibers, which have environmental and weight problems, and run from 60 cents to $10 dollars a kilo.
Germany and France are using hemp for construction material, replacing drywall and plywood. A French company has built over 250 homes using hemp materials. Hemp homes have also been built on the Pine Ridge Reservation in South Dakota. Using hemp is economically smart and ecologically appropriate. What are we waiting for?

HEMP Architecture and Construction Building Materials

Hemp building material could allow us to replace the need for wood, bricks, and fiberglass insulation. The market potential for Hemp in building materials for home and industry is gigantic.

Once Hemp can be grown on a large, economically competitive scale, manufacturers will see that it outperforms other natural fibers due to its length and strength.

Building and construction materials are sourced from the Hemp plant's tough fibres. These include the bast fibres (or "bark") composed of 53-74% cellulose and also the interior "hurd".

Currently, there are two primary uses of Hemp in building and construction that have advanced to the point of commercial availability and economic feasibility. These are the development and utilisation of Hemp fibres as composite fibre products like medium density fibreboard (MDF), and other cellulosic composites, and products made from Hemp hurds mixed with lime.

 Hemp mixed with lime has been used as a building material in France since the time of Charlemagne - between 500- 751AD, but is only now being re-discovered. Now it's being used to make floors, walls, bricks and insulation panels.

Trials of Hemp building products are presently underway in Queensland, with a promising future.

"Why use up the forests which were centuries in the making and the mines which required ages to lay down, if we can get the equivalent of forest and mineral products in the annual growth of the fields?"

Hemp’s many qualities offers great benefits for domestic housing needs.

1. Excellent acoustic insulation

2. Breathes, prevents condensation

3. Self-draining and waterproof

4. Non-flammable (no toxic combustion products)

5. Resistant to rodents, termites, insects, fungi & bacteria

6. (because of silica content)

7. Easy to use, flexible and crack-resistant.

8. Ideal for cyclone and earthquake prone areas due

9. (strength/weight ratio)

10. lightness (appreciated in floor renovations)

11. Able to use fewer finishing touches; no plaster, painting or wallpaper required.

The task of testing, evaluating, publicising and popularising the extraordinary characteristics of Hemp products as eco-solutions in the construction industry has only just begun. It's clear though that Hemp offers an innovative and resource efficient alternative for ecological construction.

The number of industrial applications for non-wood fibers is growing every day and Hemp is the premier alternative source. To date, niche markets have been successfully developed in England and France for Hemp to act as a replacement or additive to packaging, fiberboard, cement and even animal bedding.

Hemp resists seepage, and so Hemp cement is applicable for pouring onto a soil base to make a foundation floor. The floor insulation hardens into a solid mass that will not shift under pressure.

Concrete pipes can be made out of Hemp fiber that cost 1/3 that of polypropylene. These Hemp-crete pipes have greater flexibility, greater elasticity, and are resistant to cracking.

Stones can also be made out of Hemp by wetting the stalks cellulose, and forming it into a hard black rock which can be cut, drilled, cast, carved, or formed into any shape.

A Hemp - hurd substance covered with coal-based bitumen , called Mehabit from Germany is sticky, and when leveled out on a Hemp cement floor, will dry to form a thermally and phonetically insulated floor.

Washington State University has produced Hemp fiberboard that is lighter, twice as strong, and three times as elastic as wood fiberboard, plus it has sound proofing and pressure isolative characteristics absent from wood fiberboard. These Hemp composites are also resistant to pests, moisture, and funguses.

The process involves chipping the Hemp stalk, bonding it together with resins and glues, and clamping it down into molds under high pressure until it hardens.

Germany and France are using Hemp for construction material, replacing drywall and plywood. A French company has built over 250 homes using Hemp materials. Hemp homes have also been built on the Pine Ridge Reservation in South Dakota.

Using Hemp is economically smart and ecologically appropriate. What are we waiting for?

You can build a house with hemp. Today it is being used to produce caulking, cement, fiberboard, flooring, insulation, paneling, particleboard, plaster, plywood, reinforced concrete and roofing. The hardened material is resistant to rotting, rodents, insects and fire. It is many times lighter than cement and provides both thermal and sound insulation.

Fiberboard made from hemp is twice as strong and three times more elastic than fiberboard made from wood. Because of its superior strength and flexibility, it is resistant to cracking and breaking and therefore excellent for areas susceptible to hurricanes, tornadoes and earthquakes.

Hemp oil has a natural drying agent and is used in paints, varnishes and sealants which render wood highly resistant to water. In fact, up until 1937, all quality paints were made with a base of hemp oil.

Hemp Hurds

Currently efforts are underway to use the Hemp hurds or shives in the production of ecological particle boards and building materials. Hemp hurds are not only very absorbent, (hence their commercial use today in animal bedding in the UK and EU) but they are also uncommonly rich in silica, a chemical compound naturally occurring as sand or flint.

When mixed with lime Hemp hurds change state, from a vegetable product to a mineral, in effect "petrifying" or turning to stone, yet weigh between 1/5 and 1/7 that of cement Most popular to date has been the French Hemp product Isochanvré made by Chènovotte Habitat, which is used as a building and thermal insulation material in France.

To date over 250 houses have been constructed using this Hemp based material. Research is ongoing too in the UK and Germany, where Hemp hurds have been used for the construction of floors since 1957.

In France, Hemp hurds are now available commercially under several different brand names: "Isochanvré ", "Canabiote" and "Canomose"; and come in two forms; for construction or insulation.

The processing required is similar for both types of product. The Hemp bast fibres are mechanically removed in a dry process without chemicals or the need for a retting (rotting) stage leaving behind the interior core, or hurds. These are then "naturally stabilized" (with borax and boric acid?) to make them fire and water resistant.

For insulation this Hemp product is used in a loose form and is either poured or blown into roofing, partitions, floors or in wall cavities. Isochanvré meets the "norms" of the CSTB (Scientific & Technical Centre for Building) criteria for a good insulating material. In this application it is probably similar to the cellulose-based insulation made from recycled newspapers currently available in Australia.

Unlike these products however, Isochanvré claims one major qualitative difference - a "high thermic capacity. The term "thermic capacity" is presumably equivalent to thermal mass - an ability to store warmth and later give it back, due it is claimed, to the high proportion of silica within the plant. Chènovotte Habitat acknowledge this is unusual: "Original evaluation is in progress, as the current common insulating materials have no [thermal mass]" .

Empirical evidence from the 250+ houses constructed to date using Isochanvré suggest that this claim is valid:

In autumn, owners of isochanvré Hemp houses activate their heating systems 15 days after their neighbours"; less heat is needed in winter and humidity is lower; in summer, isochanvré Hemp slabs are 3°F cooler than the ambient air temperature.

Isochanvré is processed slightly differently for construction purposes. The product is mixed with natural lime (not cement) and water in a cement mixer. Sometimes plaster of Paris (pure gypsum) or 10% river sand is added. At this stage the compound resembles cement. It can be poured like cement, hardens and becomes mold and insect resistant . After drying the isochanvré is a lighter, tawny colour with a texture similar to cork. isochanvré claims good thermal and acoustic insulating properties.

It can be utilised in drywall construction between form work, as an interior and exterior insulation or be poured as a floor, or as an addition to the existing slab to raise the level of an existing floor. The forms can be removed within a few hours, whilst the petrification process continues. A big advantage of the material is the fact that it makes several layers of conventional building materials superfluous: Isochanvré can replace bricks or cement, a vapour barrier, insulation, and plaster board or Gyprock panelling.

The only finish required on the exterior is a coat of whitewash, with or without added pigments, whilst the interior can retain the cork-like texture by either waxing or varnishing the finished surface.  Chènovotte Habitat makes other claims as to advantageous qualities of Isochanvré which would make it an exceptional material, by any criteria; whether ecological, architectural, practical, or from the end-users perspective.

Isochanvré is marketed as an "eco-product" and makes a point of providing life-cycle analysis is a part of this. From its origins as an annual plant that supports agriculture (and hence rural areas), it provides an alternative to forest clearance for woodchipping or timber, obviates the need for mineral exploration and mining and requires no chemical processing in the defibration or stabilisation stages

From "cradle to grave" Isochanvré has a low environmental impact.. The simple, natural materials mean no pollution of air or water is caused, no waste is produced, with all sections of the plant being used, and only minimal energy is required to process it. It's uniquely packaged paper sacks made of a micro-porous material, designed to be incorporated into the insulation of either attics or floors. The lightweight nature of the product also reduces transport costs.

Isochanvré 's lime-based nature make it an easy and safe material to work with. Nor does it require any maintenance over time. In fact, the petrification process means that Isochanvré improves with age, an important ecological consideration. It is also biodegradable.

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