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Making Paper From Seaweed and DIY Hempcrete Instructions!


aper Making and Hemp-Crete: Bringing Nature to Homes

Written By: Sumedha Chandra Sekhar


Before the 1900s and its vilification by the US Government and the artificial textile companies(Dupont) as well as the lumber industry (Hearst), Hemp was one of the most significant crops amongst humankind. However, now it is most widely recognized through years of intense propaganda as nothing but a plant that "gets one high." Considered to be one of the first plants ever spun into usable textile fibers more than 10,000 years ago, hemp is now finally moving away from its century-old reputation as we find more industrial uses for it every day. Some of the more famous uses are food, paper, clothing, beauty, and biofuel. The modern consumer can find hemp milk, protein powders, cooking oils, breads, plastics, lightweight automotive body materials etc. But one of the biggest untapped uses of hemp is construction material, also called Hempcrete.

Hempcrete is said to be the most sustainable building material and a better alternative to concrete and steel because it gets stronger as it gets older. Mixing Hemps woody fibers with lime produces a natural light concrete that preserves thermal mass and is highly insulating. It is fire, pest, and mold resistant with good acoustics, low humidity and effective at regulating temperature. The material is carbon negative, meaning its construction consumes more carbon than it produces thus the carbon footprint is almost negative, as carbon is literally locked away inside the material. The only drawback? Growing this green building materials can land you in jail since the plant's farming is highly controlled in most countries and requires a license.

Typically planted in the months of March and May in the northern climate, Hemp plants take only four months to grow from seed to harvest. They are then cut by hand and let too dry for a few days before bundled up and dumped into vats of water to swell the stalks. The dried fibers are mixed with lime, and the result is a lightweight installation material and when fully cured, the hempcrete blocks float in water!

More like drywall than concrete, it is not used as a structural element or for the foundation as it is an insulation which needs to breathe. It should not be used at ground level either as it would lose its resistance to mold or rot. Lime plaster coating is also necessary to be applied to anything that touches hempcrete otherwise the lime can harden and thus lose its ability to absorb and release water. Most often, it's mixed on-site and poured directly into a frame.

In many climates, a 12-foot hempcrete wall can help maintain an approximate 60-degrees indoor temperature year-around without cooling or heating systems which can overall lower the environmental footprint dramatically lower when compared to traditional construction.

Hempcrete was first discovered in France in the 6th Century, so why isn't it more popular you may ask?

A popular material used in Europe for decades, a New York Times article paints us the European-hemp picture, "Hundreds of buildings now use hempcrete, including a seven-story office tower in France, a Marks and Spencer department store in the United Kingdom, and even a home built by Prince Charles." Almost any house that can be built with brick and steel can be built with hempcrete and a structural frame. In the United States, special permits are needed to build with hemp, and requirements often vary by county and state. The first modern residential hemp structure was constructed in 2010, in North Carolina. The crop was imported from the UK.

In 2016 Israel's first Hemp house was completed. Some 1,000 hemp bales (30 tons) were exported from France. The Tav Group Architects, an Israeli firm, designed the 250 sq. meter home. About half the house is made from hempcrete, the rest is local stone, rammed earth and wood. The architect Maoz Alon described the house to be "like nature herself." "It gives you the rejuvenating feeling of the forest or a vast fresh meadow."

The Hemp crop itself requires no fertilizer, pesticide, weed killer, or fungicide. Because it grows so thickly, weeds cannot grow; thus farmers often grow it in rotation with other crops. The crop following the hemp requires no weed killer as they have all been driven out by the Hemp plant. Industrial hemp contains a mere 0.3 percent of THC (tetrahydrocannabinol), the substance that is responsible for the buzz when smoking weed. Thus, it is impossible to get stoned on an Industrial Hemp joint unless it is indefeasibly huge!

A home made from hemp smells a little like lime- bringing some nature to the home. Black Coral Inc is seeking to raise $20,000 for 3 months of 3 hour classrooms twice a week to instruct in Boston Mass and In Roatan Honduras.



Sargassum was named by the Portuguese sailors who found it in the Sargasso Sea. Sargassum is edible, it's harvested to feed livestock too, and you can fry, boil, steam or dry it. It's played a part in Chinese medicine as far back as the 8th century, treating goiters (high iodine content) — and made into tea to control phlegm. Sargassum presents risks to human health as well. In the water, it's harmless to humans, but the trouble begins once it lands on the beach and starts to decompose. The decomposition of beached sargasso begins 48 hours after washing up. It then releases hydrogen sulfide (H2S) gas and ammonia. H2S is a broad-spectrum poison that smells of rotten eggs.

Breathing in these toxic gasses may cause respiratory, skin and neurocognitive symptoms in people that come in close contact with degrading sargasso. In 2018, in Guadeloupe and Martinique, there were 11,000 cases of suspected poisoning reported. Patients complained of heart palpitations, shortness of breath, dizziness, vertigo, headache, and skin rashes.Since 2011, blooms of Sargassum have wreaked havoc on tropical shores because of climate change ocean warming that was when the seaweed first began arriving in unexpectedly large waves.

Similar pileups have occurred almost every year since from 2018-2022 we see the problem growing too large to handle for local economies. Some countries have set up nets to block the incoming algae, or hired companies to clear affected beaches with daily backhoes and dump trucks. This negative impact can be turned into an opportunity for locals if they are taught how to make goods and products from this seaweed that would boost indigenous economies and protect the beaches and flora and fauna in the surrounding areas. Black coral Inc has discussed bringing this knowledge to the community leaders of several Caribbean ports of call including Roatan Honduras and Kingston Jamaica.

Using a model established in Mexico. Mexico’s roughly $23-billion-a-year tourism revenues were in jeopardy so government’s science and technology council, Consejo Nacional de Ciencia y Tecnología, started funding a research project with the Polytechnic University of Quintana Roo to try and turn the sargassum seaweed problem into a sustainable business opportunity. One of the properties in sargassum seaweed is sodium alginate which, when extracted, can be turned into a thickening agent used in pharmaceutical products and creams. The global sodium alginate market is worth around $624 million a year and is expected to grow to almost $1 billion by 2025.Another potential sustainable business use is as a biofertilizer in the agricultural industry. A study out of Texas State University tracks the degree to which massive drifts of sargassum can be converted into usable compost.

Among the concerns realized by attempting to use sea matter applied to garden growth is the detrimental effect salt content can have on land-based plants. However, this study found that prewashing salt content in Sargassum binderi decreased salt content from 17.23-14.89% then by soaking sargassum for 5-7 days and washing again it could be incorporated into compost piles with no detrimental effects because of high levels of salinity. “Since pre-washing of the seaweed did not impact the final compost produced in terms of improved quality! The final way to prosper from Sargassum is from soap and papermaking!

In the face of extreme weather events, such as droughts, floods, and cyclones, water-borne diseases are of particular concern in the tropics. Poor hygiene practices and lack of improved water and sanitation infrastructure in rural areas are all factors that lead to increased diarrheal illness. Handwashing with soap is the most effective and inexpensive way to prevent the spread of disease. But for many rural households soap is sometimes considered a luxury item. The seaweed contains beneficial minerals and vitamins that nourish and revitalize the skin. It is also used to promote weight loss, heart disease and strokes.

Seaweed Soap Recipe


This is a large batch recipe making around 12 bars of soap.

1 Quart coconut oil

1 Quart seaweed extract or puree’

1 cup caustic soda (lye)


Mix coconut oil with 3 cups of seaweed extract or Sargassum puree.

Mix the remaining cup of seaweed extract with caustic soda in a separate jug. Stir slowly until dissolved.

Add the oil mixture to the caustic soda mixture and continue stirring for 40 – 45 minutes.

Pour the liquid into a hard plastic mold/container and leave to cool for 1 hour.

(Note: Dried rose petals and lavender work beautifully in making more aromatic soaps. Herbs including lavender, calendula, and chamomile make beautiful flowers for soap making as well. Used coffee grounds are good for both melt and pour and cold process soap. Dry grounds can bleed in the soap, creating a halo of color. After making a pot of coffee, place the grounds on a towel and pat dry. A general usage rate is about 1 teaspoon per pound of soap

Use a knife to slice the soap into smaller squares and do not touch for at least 3 weeks.

Ready to use after 3 weeks.

Black Coral Inc is seeking $10,000 -$20,000 for 3 months of 3 hour classrooms twice a week to instruct in Boston Mass and In Roatan Honduras.


The process involves collecting the seaweed, boiling it and letting it dry in order to get rid of any microorganisms it is carrying. The sargassum is then hydrated again using a water solution containing salt. bleach, and other additives which eliminate its offensive smell. The next step is to turn the seaweed into a paste into which recycled paper from garbage and discarded notebooks or newspapers is mixed. The non-fibrous parts of the sargassum, which are basically made up of fulvic acids and polysaccharides, give improved characteristics to the cellulose fiber paper even when used in small quantities. Particularly, the use of sargassum gives the paper better mechanical characteristics such as resistance to bursting, stiffness and resistance to fats and solvents. “When the paper from the sargassum can be mass produced, the world’s forests can be saved. The positive impact of prevention of cutting trees is to minimize global warming.

Sargassum also has an extra advantage of not producing pollutant by-products, thus circumventing the creation of further ecological problems caused by disposal


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