Sky rocketing prices for building materials have been a common complaint from home builders over the past year. The costs of lumber, steel and concrete have all soared, and now some are promoting the idea of hemp as a more affordable alternative.
Hemp does contain cannabis, but the concentration of THC is much, much lower so it has never been used as a recreational drug. On the other hand, it has traditionally been used to make textiles, paper, and food. More recently, it has even been used as an alternative to corn in biofuels. And hemp pellets can be burned for fuel too.
Another potential use is hemp-based plastic, which is biodegradable and both cheaper and stronger than petroleum-based plastics.
And what of building? Well, as Think Realty explained in a recent post, it can actually be considered a kind of wonder material, with dozens of possible applications. For instance it can be used for insulation, where it provides higher ratings than other types of materials and is lighter and easier to use. It can also replace concrete. So-called “hempcrete” can be used to manufacture blocks (pictured), panels and even 3D-printed shapes for walls and floors. Hempcrete isn’t suitable for load-bearing walls, mind you, but hemp adobe is. It’s a mix of refractories, water, and hemp and it has a very quick set time and excellent thermal and structural qualities that surpass even concrete.
Hemp is a replacement for wood too. It can be extruded just like lumber can, in order to make boards, wood blanks, plywood – you name it. It has a similar level of hardness to oak. Best of all though, while a softwood lumber tree takes around 40 years to grow, hemp can grow in just 90 days. It grows at about the same speed as bamboo, and it’s possible to get three growing seasons per year in some parts of the U.S.
It’s environmentally-friendly too since hemp sequesters greater amounts of carbon from the atmosphere than other crops. So hemp buildings have the potential to be carbon negative if done right, Think Realty said.
To sum it up, hemp can be used in everything from footings to floors, roofs and walls, insualtion, shingles and more. It can replace bricks and blocks, can be used to make cabinets and sheets. It’s also incredibly resistant to mildew, mold, pests such as termites and it’s a natural fire retardant.
The only problem is hemp’s reputation. Because it was grouped with marijuana so long and illegal to grow until 2018, few people are aware of the benefits. So its use in construction remains uncommon.
That could be about to change. At present there’s still no hemp supply chain in place for the products to go from farms to those who can make it into hempcrete or hemp lumber. Smaller companies are trying to do that though, so it may not be too long before we start seeing more hemp homes in the U.S
“Within the next few years you will begin to see hemp homes and hemp alternatives for lumber, concrete and steel,” Steve Streetman wrote in Think Realty. “When a product is better, cheaper and faster, as well as more environmentally friendly, it can’t be held down for long now that it’s legal and the rules for growing it have been developed.”