Move Over Cotton, Say Hello to Hemp – The ‘Forbidden’ Crop That’s Taking the World by Storm

Move-Over-Cotton-and-Say-Hello-to-the-‘Forbidden’-Crop-That’s-Taking-the-World-by-Storm-Thomas-Jefferson-Hemp-Quote1-300x198

 

(Click on the image (above) for the original article.)

Contributing Writer for Wake Up World

The Declaration of Independence was drafted on it. The American Founding Fathers urged the fledgling country to grow it. And the first paper was made from it 1,900 years ago. Hemp. It’s one of the most versatile and sustainable cash crops on the planet. For all it’s merits, however, the plant has also been on a “no-grow” list for over seventy years in the United States, due to draconian laws established by the Drug Enforcement Administration (DEA). Thankfully, that’s all about to change.

A Modern-Day Gold Rush

As one of the oldest cultivated crops, hemp has a rich and colorful history. Cloth, paper, food, building materials, fuel, plastic — you name it, and there’s a good chance it can be made from the plant.

Canada has fully embraced the recent demand for hemp and subsequently grows it to the tune of almost $1 billion a year, which equates to $250 net profit for each acre. Compare this with soy, the United States version of a major crop, which averaged around $71 per acre in 2014.

The Los Angeles Times reports:

“Canada’s windfall has been largely due to the American demand for omega-balanced hempseed oil. But hemp is also a go-to material for dozens of applications all over the world. In a Dutch factory recently, I held the stronger-than-steel hemp fiber that’s used in Mercedes door panels, and Britain’s Marks and Spencer department store chain used hemp fiber insulation in a new flagship outlet. “Hempcrete” outperforms fiberglass insulation.”

Move-Over-Cotton-and-Say-Hello-to-the-‘Forbidden’-Crop-That’s-Taking-the-World-by-Storm-Hempcrete-300x292

While Canada reaps the financial benefits of the plant, the U.S. still lags behind. In a step towards legalizing hemp for industrial uses, President Obama removed it from the Controlled Substances Act in 2014 — as long as it was used for agricultural research. All the same, a number of states are weary of the snail-like pace of the Feds and are taking matters into their own hands — by passing legislation to import hemp seed for pilot programs. But the DEA has been slow in reading the memo.

In May 2014, the agency seized a 286-pound shipment of Italian hemp seed bound for Kentucky’s state agriculture department. “After a weeklong standoff, a federal agency had to be reminded by the federal courts that the law had changed and Kentucky’s seed imports were legal,” writes the Times.

Cotton vs. Hemp

Political shenanigans aside, one of the most desperately needed uses for the plant involves the creation of durable and eco-friendly fabric — especially considering the damaging effects of conventional cotton production. Plainly put: pesticide-riddled cotton is an ecological and health nightmare. The crop requires massive amounts of irrigation, and is largely grown in dry regions of the world where water is scarce, like Egypt, China’s Xinjiang province, California and Texas.

Move-Over-Cotton-and-Say-Hello-to-the-‘Forbidden’-Crop-That’s-Taking-the-World-by-Storm-Hemp-Dress-228x300

The devastating effects of the crop are seen in places like the Aral Sea in Central Asia. Formerly the world’s fourth largest inland lake with a robust ecosystem, the sea has been reduced to a meager 15% of its previous size — largely due to irrigation required by the cotton industry. Compounding the problem, farmers are using increasingly more water on their fields in an attempt to combat the rising level of water and soil salinity in the area.

On average, it takes 1,800 gallons of water to grow enough cotton for one pair of blue jeans.

Water consumption isn’t the only issue with conventional cotton, pesticide use on the crop is notoriously high too. As the most pesticide intensive crop on the planet, cotton agriculture harms and kills countless farmworkers around the world every year. One pesticide, aldicarb, is particularly dangerous. It’s deemed “extremely hazardous” by the World Health Organization and a single drop absorbed through the skin is sufficient to kill an adult. And yet, aldicarb remains a popular choice in cotton production. Herbicides and chemical defoliants add to the toxic nature of the plant — all of which typically stay within the finished fabric for the lifespan of the clothing, and are assimilated through the skin. The same is true for bedding and furniture.

The Pesticide Action Network paints a bleak ecological picture of the crop:

  • Nearly $2.6 billion worth of pesticides are sprayed on cotton fields each year — accounting for more than 10% of total pesticide use and nearly 25% of insecticides use worldwide.
  • A 1997 Danish television documentary showed methyl parathion being sprayed on cotton fields in Nicaragua and Guatemala while children played in and beside the fields. It also documented numerous cases of methyl parathion poisonings in cotton production.
  • Fish in Alabama: In 1995, pesticide-contaminated runoff from cotton fields killed at least 240,000 fish in Alabama. Shortly after farmers had applied pesticides containing endosulfan and methyl parathion to cotton fields, heavy rains washed them into the water. The Alabama Department of Agriculture and Industries stated that there was no indication that the pesticides were applied in an illegal manner.
  • Australian Livestock: Australian beef was found to be contaminated with the cotton insecticide Helix® (chlorfluazuron) in 1994, most likely because cattle had been fed contaminated cotton straw. In response, several countries suspended beef imports from Australia. One year later, farmers were alarmed to discover that newborn calves were also contaminated with Helix, apparently because it passed through their mother’s milk.
  • Birds in Texas: A breeding colony of laughing gulls near Corpus Christi, Texas, was devastated when methyl parathion was applied to cotton three miles away. More than 100 dead adults were found and 25% of the colony’s chicks perished.

 

Move-Over-Cotton-Say-Hello-to-Hemp-The-‘Forbidden’-Crop-That’s-Taking-the-World-by-Storm-

A Better Way

When we examine the environmental and health impacts of cotton, hemp stands out as a winner for a number of reasons.

  • Hemp produces up to three times the amount of usable plant material per acre than cotton.
  • Requiring very little pesticide or fertilizer, hemp is a robust crop that can grow in a variety of conditions/soils.
  • Water use for hemp is about half of what is required for cotton.
  • Unlike cotton, hemp actually enhances the soil. With long roots up to 6 feet deep, the plant aerates and breaks up soil. It also helps to clean soil contaminated with heavy metals, solvents, pesticides and gasoline.
  • With 3-8 times the tensile strength of cotton, and 4 times the warmth and absorbency, hemp is an exceptionally durable fabric.
  • Hemp breathes and wicks moisture away from the skin more efficiently than cotton.

Even with all the ecological advantages of hemp, the motivating force for industrial change always comes down to profitability. Happily, hemp covers that aspect too. Says Doug Fine in theLos Angeles Times:

“We’re down to 1% of Americans farming; it was 30% when our world-leading hemp industry was stymied in 1937. The crop is more valuable today than it was then. We should be waving flags and holding parades for the farmers ready to plant the crop that Thomas Jefferson called “vastly desirable.” I know I’m ready. To cheer, and to plant.”

Article sources

Previous articles by Carolanne Wright:

About the author:

Carolanne-Wright-145x150

Carolanne enthusiastically believes if we want to see change in the world, we need to be the change. As a nutritionist, natural foods chef and wellness coach, Carolanne has encouraged others to embrace a healthy lifestyle of organic living, gratefulness and joyful orientation for over 13 years

Through her website Thrive-Living.net she looks forward to connecting with other like-minded people from around the world who share a similar vision. Follow Carolanne on Facebook, Twitter and Pinterest.

Lime Plaster; Making My Hempcrete Build Feel Finished

I love talking about hempcrete building.  However, it is a little leap for most, including me, to think of eliminating all the layers in a traditional build.  I get lots of comments like, how will you keep the moisture out without a vapour barrier?  Will the walls look industrial-like when we’re all done?  And my personal favourite, can you paint the exterior and interior walls different colours?

First of all, you want the walls of your hempcrete home to breath.  This is really important for the insulation factor of the building.  This counterintuitive measure is what actually increases the R-factor so you don’t want to seal off the building with a traditional vapour barrier or you actually compromise the efficacy of the hempcrete.

upnh_HMext

Also, if you take a look and traditional homes in England, where the climate is very wet, you’ll see post and beam construction with lime finishes everywhere.  Lime is actually a calcium based slake that can be crushed to a powder and applied as the smoothest of finishes with a little water and a fine trowel.  And yes, with some stunning milk paint, you’ve got a gorgeous finish.  Take a look here:

Lime Plaster 101: the basics

by Sigi Koko

Lime is a confusing term, because it can refer to various chemically different (but related) materials.  (Not to mention the citrus fruit!)

For example, cured lime plaster, chemically speaking, iscalcium carbonate…basically limestone.  But theuncured material that goes on the wall, is also called “lime plaster”…but it is calcium hydroxide to a chemist.  Yikes!

So let’s go through some of the basics of lime to give you a great understanding of the ins and outs of how to use it.

What’s the big deal about lime plaster?

Lime has been used for thousands of years as a fabulous binder in mortars, plasters, and paints.  It wasn’t until the post-World War II housing boom that quick-setting cement products eclipsed lime in construction.  Lime cures more slowly than cement, but it holds many advantages because it is a workable, self-healing, breathable, nearly carbon neutral material…making it a great choice for natural building.

Why is lime plaster aligned with natural building?

First, lime-based products have a smaller carbon footprint than their ubiquitous cement counterparts.  Cement production creates 1.25 pounds of CO2 for each pound of cement produced, whereas lime is nearly carbon neutral.

Second, and perhaps most importantly, lime is what’s called “breathable”.  Breathability refers to a material’s ability to allow air-borne vapor, ie humidity, to pass through it.  Think Gortex…water-repellent and vapor permeable.  The breathability ensures that moisture will not build up inside the wall system.  In turn, this ensures that any biodegradable materials, such as wood or straw, are protected from decomposing.

upnh_084

How is lime made?
(a little chemistry…)

  1. Limestone, shells, or other material that is high in Calcium Carbonate is burned in a kiln.  The heat drives off Carbon Dioxide, leaving Calcium Oxide. This is also called Quicklime.
  2. Quicklime (Calcium Oxide) reacts with water in an extremely heat-producing reaction, a process called “slaking”.  The result is Hydrated Lime, or Calcium Hydroxide (since hydrogen from the water bonds to the Calcium Oxide molecule). This reaction can be quite dangerous, so it is common to purchase Hydrated Lime (Calcium Hydroxide) instead of Quicklime (Calcium Oxide).
  3. Once Calcium Hydroxide is exposed to air (whether it’s in powder or putty form), the lime reacts with Carbon Dioxide in the air and ends up where it started…as Calcium CarbonateSo except for the energy of the kiln, the lime is carbon neutral.

Because lime plasters react with carbon dioxide from the air in order to harden, you can easily keep the calcium hydroxide form of lime in its putty form indefinitely by storing it with an inch or so of water on top of it (or in a completely air-tight container).  This effectively prevents the lime from getting into contact with air and thus prevents curing until you are ready to use it.

upnh_082

How is plaster made?
(tips for mixing, & applying)

THE PROPORTIONS

For general lime plasters (especially on the exterior), I use 3 parts sand to 1 part lime (calcium hydroxide).  This is a great all-around mix that is sticky enough to work and cure strongly, yet with enough sand to prevent lots of cracking.  If you intend to work your finish to tighten and smooth it out, you can use a more “lime rich” ratio of 1:2 (lime:sand) or even 1:1 for very very finely worked plasters.

THE MIXING

Lime putty increases plasticity and workability the longer it is mixed.  So the longer you mix it, the creamier and easier to spread it gets.  (Magic, right?)  I mix in a mortar mixer (not a cement mixer!) for at least 20-30 minutes.  Only add water (a small amount!) if your mix is extremely thick.  The plaster should be stiff but should spread easily, like cream cheese.  Allowing the mixed lime plaster to sit overnight improves workability, but remember to remix the plaster again before using.

 

THE WALL PREP

To prepare strawbale walls for lime plaster, first shape your walls exactly how you would like them to look once plastered.  It is time-consuming to build up the lime plaster to fill in large voids (since it must be applied in thin coats).  Next, install expanded lath (not chicken wire!!) to cover any slick surfaces, such as wood…anything that is too smooth for plaster to hold onto.  Make sure your lath bridges across the wood and at least 6″ into the straw so you don’t get a crack right where the lath ends.  I do NOT recommend using lath over all of the strawbale, unless you live in a seismic region and your code requires this.

 

Be sure to dampen your walls down well before applying each coat of lime plaster.  For the first coat, this means soaking the strawbales until they are damp and the straw is pliable.  For each subsequent coat, soak the wall down the day before you will plaster, again the morning of plastering, and throughout the day keep the wall damp as you work.  Otherwise the wall steals moisture out of your plaster quickly, and can pop the bond that holds your plaster on the wall.

 

APPLYING THE PLASTER

I generally use 3 coats of lime plaster for exterior walls or showers.  You can use 1 or 2 coats for decorative interior finishes.  The first coat can be up to 5/8″ thick if it is applied to strawbale, otherwise each coat should be a maximum of 3/8″ thick.  Any thicker and the lime cannot absorb carbon dioxide adequately for curing to fully take place.

 

I apply the plaster with a wooden float to create a well-shaped wall that has decent texture.  For the finish coat, I smooth the final surface using a flexible pool float.  You can continue to buff or polish the lime as it is curing for a very smooth sheen.  There are many highly refined finishes that can be achieved with simple lime plaster.

 

Score the surface of each coat (except the finish plaster) to create lots of surface area for the next coat of plaster to key into.  And allow at least 7 to 10 days between coats to give each ample time to cure.  (Also see the next section for curing tips.)

 

NOTE: I do NOT recommend lime plaster over clay plasters for exteriors in wet climates.  The clay substrate shrinks and swells depending on moisture content.  The cured lime cannot shrink and swell with the clay and so it will be more susceptible to cracking when used over clay plaster in a wet climate.  Lime can be used over solid clay walls, such as cob & adobe, because there is so much more clay present to absorb ambient air moisture without measurable swelling.

 

upnh_2000162030337097207942744844n

THE CURING PROCESS

You want the lime to cure…NOT dry out.  That means it needs to react with carbon dioxide from the air before all of the moisture evaporates.  If it dries out before it has cured (and converted into calcium carbonate), the resulting plaster will be weak and possibly crumbly.  So protect the plaster from wind and sun until it has cured, and it helps to dampen the wall daily as it is curing.

 

Do not apply exterior lime stucco if there is any risk of freezing, otherwise moisture in the plaster can freeze, expand, and cause critical failure of the plaster.  The temperature needs to be above 40 F for at least a week to keep the curing process going.

 

upnh_010

Some nitty gritty details
(and where to find materials…)

SAFETY FIRST!

Note that lime is highly alkaline, and can severely burn your skin.  Unlike acid burns, you generally do not feel an alkali burn until the damage has been done.  So please use full protective gear whenever working with lime, including elbow-length rubber gloves, long sleeves, eye protection, etc.  If your clothes get lime putty or lime water on them, change, so the lime is not in contact with your skin through your clothing.  I always keep a bucket of water & vinegar nearby to neutralize my tools, gloves, and hands as I’m working.

 

WHAT KIND OF LIME TO USE?

I use fresh hydrated powdered lime and then soak it on site from the very beginning of construction (ideally several months).  The longer you soak it, the creamier and easier to trowel your plaster will be.  I have had most consistent results with vertical kiln products fromMississippi Lime.  The vertical kiln operates at a lower temperature and so there is less inert material in these products, meaning they are very high in purity and total calcium content.

 

I ask for bags that are date-stamped less than 6 months prior to purchase.  This ensures the lime is fresh.  If it has been in the bag for a long time, it gets exposed to CO2 in the air and begins to carbonate and become inert.  Powdered lime that has converted to calcium carbonate looks identical to calcium hydroxide (hydrated lime), but when you soak it, it will not get very thick and when you put it on the wall it will dust or crumble.

WHAT KIND OF SAND TO USE?
Choosing the sand for your plaster can seem mundane and unimportant.  But that is not the case!!  The key variable is that the sand must be “angular”, which means it has a lot of surface area to bond with the lime.  I use “toothy” or “angular” mason’s sand for all three coats of lime plaster.  You can also use concrete sand (which is larger)…just remember that your plaster needs to be thicker than the largest particle in your mix (otherwise the pieces will drag around with your trowel).  Note that the color of the sand will impact the final color of your finish coat of lime.  If you want very white plaster, experiment with white sand.

upnh_HOWtoartesanotadelaktFBbench

CAN LIME BE PIGMENTED?
Yes!!  Any pigment that can be used in concrete will work with lime.  The pigments must be able to handle the alkalinity of the lime.  Mineral pigments generally are fine, plant-based pigments generally will not work (they change color and fade due to the alkalinity).  In any case, do several test patches to confirm how much pigment to add to achieve your desired color.

upnh_TIPSearthenbuiltFBcolortesting

To follow Sigi Koko at “Down To Earth Designs” and perhaps take with her in Maryland or Pennsylvania, follow her offerings at Sigi Koko at Down To Earth Designs.