Constructing the Future

from Louisiana Hemp Magazine Volume 1 Issue 2

Mountain Climbing

Contractor Sets Sights on Building Hempcrete Homes in Louisiana

By Abby Meaux Conques

Joseph Strong, Louisiana native, is a licensed contractor & owner of Strong Construction, LLC.

He holds various certifications and a construction degree from the University of Louisiana at Monroe. He’s also an advocate of a construction material formed with hemp, called hempcrete.

Strong’s post-graduation construction career working for builders in California planted the seeds of green building for the current business owner. *green building refers to both a structure and the application of processes that are environmentally responsible and resource-efficient throughout a building's life-cycle: from planning to design, construction, operation, maintenance, renovation, and demolition.* “My time spent there opened my eyes to a lot of different ways of doing things than how we’re used to doing them here in Louisiana...concepts like what kind of carbon footprint we’re leaving for future generations and building sustainable and environmentally conscious structures,“ Strong explained.

“I attended many green building conventions and sought the new things businesses were implementing in order to lower carbon emissions in the building process and constructing sustainable subdivisions.“ Strong utilizes various concepts in his building specifications – namely solar panel use and the like.

Then, one day in 2012, a friend introduced him to the concept of hempcrete. The concept is not a new one globally. It gained popularity in Europe in the 1980’s to remedy post World War II builds which used concrete which began to fail due to water permeation. The lime / hemp mixture yielded better results than concrete. Hempcrete was also the substance favored when used throughout France to restore medieval timber framed buildings, as it was the closest consistency to wattle and daub.

In Japan, there’s a historical hemp house in Nagano that was found to be built in 1698. Today, it’s recognized as a Japanese National Heritage Site and has survived earthquakes and tsunamis. In India, the famous Ellora Caves (dated to be 1,500 old) have been preserved by hemp plaster walls. The fire-resistant hemp plaster also absorbed heat, kept insects at bay, and absorbed up to 90% of airborne sound, which made a perfect dwelling place for the monks who resided there. The Ellora Caves are a World Heritage Site.

Strong was able to connect with various professionals in the hempcrete arena via various social media platforms. “These guys are elders in their communities and are eager to pass down their knowledge to people who want to absorb it. I’m lucky that I get to converse with these guys and use the concepts they’ve learned over decades of application.”

In the United States there are only 50 to 60 Hempcrete-built homes. Five of those homes are built in Asheville, North Carolina.

”People may think they can read some books on the subject and do this. I’ve been in construction since I was 18 and I’m 43 now; I thought I could probably figure it out. I quickly realized you need proper training and hands-on building with the material to understand how to use hempcrete effectively.”

Strong decided to make an investment in his own hemp knowledge and attend an extensive workshop in Asheville in 2017 with hands-on learning on how to build hempcrete homes. He was instrumental in the construction of the fifth Hempcrete home built in Asheville. One of the connections he made in Asheville was Henry Valles. Valles is a notable Hempcrete building consultant in Austin, Texas who constructed a homeless shelter on donated land to help individuals get back on their feet after facing tough times. Valles served on the early adopters speaking panel in October of 2019 at the US Hemp Building Summit. Valles’ contribution of building a sustainable shelter for the homeless community inspired Strong to make this one of his goals to do the same in Louisiana.

Strong joined the Hemp Industries Association and after attending various hemp conferences, Strong and met builders that he was turning to for advice on the new (to us) concept.

“It was exhilarating to meet these like-minded people in person...there’s comraderie to be found in support of the same concepts. When I went to Mexico and connected with some of the builders there, we spoke about how we were all fathers to daughters...and that one of our driving forces was to leave the planet better than we found it. So here I was with this group of men that I never met, connected with them on so many different levels,” Strong mentioned. The group in Mexico built a sustainable Hempcrete structure to replace a school that was previously destroyed. One of the main reasons for the build was to teach the school children about sustainability.

WHAT MAKES HEMPCRETE DIFFERENT?

Hempcrete is composed of hemp, lime and water. It’s 85% cellulose and sequesters carbon, even while in the field. Hemp is like silica and binds with the lime. It has a high thermal mass so it traps air inside the walls. “It basically exhales and inhales, letting the walls breathe - this lowers HVAC tonnage as the house sequester carbon for life,” Strong explained. It’s strong, lightweight and breathable, energy efficient, offers incredible insulation, is naturally non-toxic, lasts hundreds of years and is carbon negative. Over time, hempcrete gets stronger and eventually hardens to the extent that one would find in petrified wood.

As for the benefits of hempcrete, the list is impressive. For one, it’s fire resistant. As recently as February, the company Hempitecture out of Idaho, sent hempcrete sample specimens to a ASTM E 84 testing lab. These tests are utilized by code officials and regulatory agencies in the acknowledgment of interior finish materials amongst others. They ascertain the burning behavior of materials by noting the flame spread along sample specimens. Flame spread and smoke developed indexes are reported from the testing. The results are based on a 0 to 450 scale. Hempcrete scored 0, the highest possible rating. Hempcrete is also mold resistant and termite resistant.

On a variety of levels, Hempcrete surpasses traditional building techniques. So how does Hempcrete hold up in the construction costs of traditionally built homes?

In the long run, one could save 30 to 40% of construction costs since only one product is used for construction of the home as opposed to 4 or 5 materials. Building a traditional

home uses different products such as insulation, gypsum board, Tyvek, plywood etc. “You could use the one product in Hempcrete, the finished walls look nice...a lot like the texture of stucco, the structure would be fire resistant, mold resistant, termite resistant...and you get all of those other benefits in the thermal mass insulation, negative carbon, design flexibility, significantly reduce CO2 emissions, it’s inherently air-tight, and is a no-waste product (rebuild or fertilize).”

Until recently, Hempcrete products were imported from places in the northern U.S. and Europe. This drove up the cost of building a Hempcrete home. But with the passing of the 2018 farm bill, and many farmers beginning their new hemp harvest this spring, a Louisiana Hempcrete home could be built completely from material sourced in Louisiana.

For Strong’s construction company, who sources his building lumber from Louisiana, using Louisiana-sourced hemp would save on costs and keep all of the building monies in our state. “It’s a win-win,” Strong explained. Another added bonus of using Hempcrete for construction is the possibility of saving 50% carbon emissions on the building of a home. “Many people don’t realize this, but 50% of our carbon emissions comes from construction materials of building things,” Strong mentioned.

WHAT ROADBLOCKS ARE THERE IN LOUISIANA IN THE BUILDING OF THE STATE’S FIRST HEMPCRETE HOME?

Strong mentioned, “I think it would be the educational process.“ He went on to explain that builders would have to first know what they are doing and get hands-on experience doing it. The educational process regarding that situation would be for someone well-versed in the industry to conduct workshops and educate builders and professionals in the construction industry on how to mix and construct Hempcrete. One of Strong's long-term goals is to make sure those types of workshops happen within the next year or so.

Another way in which education comes into play is that contractors that use this method will need to educate inspectors and structural engineers on how the system works along with the benefits of it. An added industry that would need to get on board are insurance companies. “I honestly think that once homeowners’ insurance companies understand the benefits of Hempcrete being fire resistant, termite resistant, and mold resistant, they would jump in to be a part of this process. But as it stands now, it is possible to build a Hempcrete home in Louisiana, and I hope I’m the first to do it.”

HOW EXACTLY ARE HEMPCRETE HOMES CONSTRUCTED?

Homes would be constructed with monolithic pours two feet in height around the perimeter and lightly packed. 24 hours is needed between each 2 foot pour for curing. So essentially one would build structures in 2 foot monolithic heights at a time, and can still get a structure built in the same amount of time as a traditional home build.

Like many hemp advocates, Strong believes that utilizing the hemp plant in various industries could help the state to not be so dependent on one industry alone. “This is the path we need to be on. Hemp can help farmers, growers, processors, manufacturers...everyone can benefit from hemp. Once you go hemp, you never go back.”