Hemp as a Building Material? Put That in Your Pipe and Smoke It!

Backwoods Survival Blog

Hemp is truly one of nature’s miracle plants. It can be eaten, woven into fiber, and made into paper and even oil. It is hardy and durable, easy to grow, and — believe it or not — it can be made into a variety of construction materials — from pipes to insulation to a concrete substitute called Hemcrete — that rival their industrial counterparts in cost and functionality.    

Contrary to popular belief, hemp does not contain THC — the active ingredient in its cousin, marijuana — and can’t get you high.

Brief History of Hemp as a Building Material

Until 1883, between 75 and 90 percent of all the paper made in America — including the paper on which the Declaration of Independence was written — was made with hemp. Between 70 and 90 percent of all rope and twine was made with hemp until 1937. A bridge in the South of France dated to the 7th Century AD was reinforced with hemp. In 1941, Henry Ford made a car built from a plastic that was made with hemp and wheat straw.

Insulation

Hemp insulation is a composite material, meaning the plant’s fibers are integrated with another substance.

Hemp insulation has a low U-value — a measurement that gauges how much heat move can through a particular material. The lower the U-value, the better the insulation. The U-value of hemp insulation is .04, which is comparable to the U-value rate of eight inches of fiberglass insulation.

Concrete

Hempcrete is a concrete substitute made mostly of hemp. It combines dried hemp stems with lime into slurry. The wet combination is then poured into wall forms or brick molds. The slurry hardens, creating a thick concrete-like wall with a high insulation value.

It should be noted, however, that hemp-based concrete is expensive — about twice as costly as traditional concrete. This has much to do with the fact that it is still illegal to cultivate hemp, so it must be imported.

Plastics

Hemp can be made into strong, durable cloth. The first Levi Strauss jeans were made of hemp.

Because of hemp’s semi-legal status in the U.S., hemp plastic is not mass-produced in America. It is, however, a plastic that scientists think may be stronger than steel. It uses hemp instead of petroleum and can be made to be — unlike traditional plastic — fully biodegradable.

Largely because of a smear campaign in the beginning of the 20th century by William Randolph Hearst (with competing interests in the lumber and paper industries) and the DuPont family (with competing interests in the chemical and plastic industries) to associate hemp with marijuana, its legal status in the U.S. is confusing and inconsistent.

What is clear, however, is that hemp is a green, natural, renewable resource that is a blessing and boon to builders of all kinds.

About the Author:
Andrew Lisa is a freelance writer living in Los Angeles who writes on a wide range of survivalist topics from MREs to stockpiling. He also writes on construction and home building topics like roofing repair.

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