Hemp is a natural fiber that can be used in concrete, insulation, furniture, and much more…
Hemp is not new. It has a recorded history going back over 4,000 years. You may remember hearing that George Washington grew the stuff on his plantation, which he and many others did because in pre-industrial America, it was a staple cash crop and had many uses like; cloth, sail, rope, netting, paper, and many more. The first drafts of the Declaration of Independence were written on hemp paper and until the 1890’s, most paper in the US was made from hemp. Hemp was a very common crop in the US, especially in tobacco growing states until its cultivation was outlawed in 1937, the same year that cannabis was banned. During WWII, hemp was deemed essential to the war effort and special licenses were granted to grow hemp, but by 1947, hemp was gone. Hemp farmers have been struggling ever since to draw a distinction between industrial hemp, which for all practical purpose, has no psychoactive qualities but many valuable commercial uses, and its close genetic cousin cannabis (aka marijuana) which is popular with recreational and medical users today.
Game Changer. The 2018 Farm Bill
The passage of the 2018 Farm Bill, this past December, is a sweeping piece of legislation, that bolstered farmers with the passage of The Hemp Farming Act, a bipartisan legislation delisting hemp as a controlled substance allowing for hemp cultivation to be re-classified as an agricultural commodity …breathing new life into the farming industry. This gave the green light, or as I’ve heard, started a gold rush, in a new segment of the agricultural industry. The result: a torrent of new ‘hemp’ based products will appear everywhere especially in the construction industry. Now that hemp is legal, expect to see innovative products hit the marketplace directed towards homeowners, contractors, builders, designers, and architects. Don’t get too excited. Hemp is not the answer to all your prayers, but it does have useful properties that in many ways can substitute what you are using now for faster, better, cheaper.
What we know about Hemp
Let’s start with sustainability. Hemp is a fast-growing, exceptionally strong, non-wood natural plant fiber. It’s a weed that can thrive almost anywhere in the world. Some places in the US can grow two or three crop cycles a year. Compare that to a 15 -25 year growing cycle for wood fiber products.
European and Canadian builders have a head start with access to hemp, where they have been using it for years for insulation as cost effective substitute for fiberglass, cellulose, or mineral wool. Hemp insulation has many advantages. It has a very long service life — walls opened up in France 50 years after construction showed hemp insulation looking essentially brand new. It’s composed mostly of a natural fiber (88% hemp fiber and 12% polyester fiber) with no chemical binders and no VOC off-gassing. It’s vapor-permeable and naturally repellant to mold, rodents and insects.
Some builders in Europe and Canada have successfully tinkered with a mix of hemp fibers and lime called “hempcrete,” but the wide-scale use of industrial hemp as a concrete substitute has a long way to go in research and development before being adopted in the US markets.
Almost standing alone is one of the early hemp innovators in the US, a company called, Sunstrand LLC, based in Lexington, Kentucky. Organized in 2014, this vertically integrated company is by their own admission …ahead of the curve. Since the founding, they have acquired special permits that allow them to grow and process hemp in Kentucky. They cultivate the plants, process the plants and have their own in-house product development, manufacturing, and distribution. According to CEO, Trey Riddle, Ph.D., “By 2021, we expect a global demand of over $3.5 billion for natural fiber composites in the building and construction industry. With Americans importing about $600 million worth of hemp annually from places like China and Canada, it makes sense to grow hemp locally, where it seems to thrive.” Trey emphasized that in addition to thermal properties for insulation, natural hemp fibers can be utilized in railings, molding and trim, decking, door panels, window frames, acoustical ceiling tiles, and many other building materials.
Sunstrand also supplies natural fibers to a range of other industries, including automotive, cosmetics, textiles, electrical and electronics, recreation industries and light-weight composites. But now the company is focused on a finished consumer product of its own in the form of a hemp insulation batt.
The positive environmental impacts of growing the hemp needed to make natural fiber insulation begin as soon as the seeds are planted. As the crops grow they absorb CO2 from the atmosphere and store it away. Once made into insulation, this carbon will be sequestered into the walls removing it from the environment for the products lifetime.
Theresa Guerra, a product sales specialist for building materials at Sunstrand, says that the batt is a blend of hemp and kenaf fibers. Hemp is grown locally from seed that Sunstrand supplies. To date, the company has produced enough batts to let local builders try them, but it’s still doing final testing and expanding a retail distribution chain.
For the time being, batts are being produced in one size and thickness: 15 1/2 inches by 97 inches and 3 1/2 inches thick. They cost about $1 per square foot, Guerra said. Sunstrand says that the hemp insulation functions like traditional insulation with excellent thermal and acoustical properties, breathable, “without agitating the skin like glass fiber.” The proprietary binder in the blend is fire, mold, and fungus resistant.
Adam Block, the company’s vice president for sales and marketing, says that Sunstrand developed the insulation because people were tired of fiberglass and saw only a limited number of alternatives. Asked whether the company was considering expanding its line, Block said that would depend on consumer demand. Sunstrand chose an R-13 batt because it’s the most commonly used type. Whether it would be worthwhile investing more money in research and development, engineering, and manufacturing to make other forms of the insulation it isn’t clear quite yet.
Improving Home Efficiency
In addition to the beneficial environmental impacts that natural fiber insulation provides, it also performs well when compared to other insulating material. Its high thermal mass helps keep the interior temperature of the building stable. Reducing the need for a constantly running air conditioning during extreme seasonal months.
Natural Fiber Insulation also reduces the growth of mold inside the walls of your home. This is attributed to the breathability of the material and the resilience of the insulation when exposed to moisture. Hemp can naturally absorb up to 20% of its weight in moisture, causing it to draw out any moisture that could damage the supporting frame structure of the wall. Once the moisture is collected in the insulation, it will gradually evaporate and keep the interior of the walls dry and mold free.
Noise Reduction The acoustic properties of the natural fiber insulation help reduce the sounds from nearby noise polluters. Making it a great option for buildings located in cities or near busy interstates and highw
Over the last dozen years, Doug has focused his efforts on renewable energy and energy conservation. In 2011, he co-founded the Detroit, Michigan based Greenlancer.com, a cloud-based solar energy design service and one of the Quicken Loans family of companies. More recently, he has become an advocate for PACE (Property Assessed Clean Energy) financing and partnered with Newman Consulting Group LLC, an internationally recognized team of experts in commercial and industrial energy management, to help building owners and facility managers implement energy conservation measures.
Elbinger serves on the board of directors of the Michigan Energy Efficiency Contractors Association (www.MEECA.info) and is a regular contributor to www.greeningMichigan.com, Environmental Network News (www.enn.com), Renewable Energy World (www.renewableenergyworld.com) and Construction Association of Michigan Magazine (www.buildwithcam.com). In 2016, Doug was named Director of the Michigan Sustainable Living Summit by the Great Lakes Renewable Energy Association (GLREA.org).