Hemp as new green eco friendly home build insulation

There are several homes being built in Asheville, NC using hemp.

In Asheville, it is common to see hemp being sold as food and clothing. Using it as a building material has many benefits yet restrictions in the US make it costly to use. Historically hemp has been used for food, medicine, fuel, clothing, paint, cleaners, cosmetics, paper and building materials.

In the US the growing of hemp is understandably controversial due to the illegal use of one type of hemp used as a drug. Yet the history of hemp in the world is impressive. Dating back to 8000BC agriculture and hemp textile industries begin in Europe and Asia.

In 500BC Gautama Buddha survived by eating hempseed. Herodotus records in 4590 BC Scythians and Thracians as consuming cannabis and making fine linens of hemp. In 100BC paper was made from hemp and mulberry is invented in China. In 100 AD the Roman surgeon Dioscorides names the plant cannabis sativa and describes various medicinal uses. In 600AD the Germans, Franks and Vikings all use hemp fiber. In 1150 AD Moslems use hemp to start Europe’s first paper mill. Most paper was made from hemp for the next 700 years!

In 1492AD Hempen sails, caulking and rigging ignite age of discovery and helped Columbus and his ships reach America. In 1564 King Phillip of Spain orders hemp grown throughout his empire, from modern-day Argentina to Oregon. In 1619 the Virginia colony made hemp cultivation mandatory, followed by most other colonies. The history continues in the US.

In 1776 the American ‘Declaration of Independence’ was drafted on hemp paper. In 1791 President Washington set duties on hemp to encourage domestic industry; Jefferson calls hemp "a necessity", and urges farmers to grow hemp instead of tobacco.

In the 1800’s Australia survives two prolonged famines by eating virtually nothing but hemp seed for protein and hemp leaves for roughage. Then paper was invented.

In the 1850’s the petrochemical age begins. Toxic sulfite and chlorine processes makes paper from trees possible, while steamships replace sailboats and tropical fibers are introduced. Then during the 1930’s fears lead to the outcry for cannabis to be outlawed. In 1937 the Marijuana Tax Act forbids hemp farming in the US. During the same time DuPont files a patent for nylon. This is followed by Canada prohibiting production of hemp under the Opium and Narcotics Control Act.

Yet in the US the use of hemp continued and in 1941 Henry Ford builds a car fabricated and fueled by hemp. In 1943 the Hemp for Victory program urges farmers to grow hemp only to be followed in 1955 by Hemp farming being banned once again. Since then Canada and Australia have legalized the growing of hemp for commercial purposes. In the US it continues to be illegal to grow hemp yet products made from processed hemp are sold freely.

Presently two homes are being built in Asheville, NC using hemp. The hemp is imported from England (This import obviously reduces it’s green credentials) which doubles the cost of the material. The walls are raised two feet at a time as blocks are fabricated using 4 parts hemp, one part lime and one part water. There are many benefits to hemp as a building material as the list below shows.

• Eliminates the need for sheetrock, insulation and moisture barrier
• It is breathable
• It is mold and mildew free
• Carbon negative
• Deterrent to insects and fire retardant
• Requires less lumber for framing
• Reduces the cost of insurance due to fire resistant qualities

For more information about the Asheville project see the article in the local newspaper…