Hemp houses could be greener, fire-resistant and built like Lego

A company based in Airdrie, Alta., has developed a hempcrete-and-lime based brick that its executives think may transform homebuilding.

It's sustainable, heat resistant, humidity-free — and carbon negative

The green nubs on these hempcrete blocks make them looks like giant Lego pieces, and that's how they fit together. The product is sustainable, carbon negative and a quicker build than using concrete, says Just BioFiber CEO Terry Radford. (Monty Kruger/CBC)

All in all, Terry Radford's new product — with apologies to Pink Floyd — looks to be anything but another brick in a wall.

That's because the president of Just BioFiber, based in Airdrie, Alta., believes it has come up with a hempcrete-based brick that is more than the equal of the usual homebuilding materials.

Radford, president and CEO of Just BioFiber, says his company has found a way to combine hempcrete — the wooden core of the hemp plant — with lime and water to create a building block that he believes has the potential to change the way we build homes. Radford says the product is as environmentally-friendly as it is user-friendly.

"My brother is the guy who actually invented the product. What had happened is he started working with hempcrete and fell in love with the material because it had these great properties," Radford said.

"The benefit to hemp is it's very insulative. It has thermal retention and captures CO2 while it's growing, [at a rate] four times faster than trees, so it's a carbon negative material. We're actually removing carbon from the atmosphere and storing it inside these building materials."

Lego-looking bricks

In addition to being more environmentally-friendly than traditional building materials, the bricks resemble giant Lego building blocks, and offer superior cooling and heating properties, Radford says.

"The No. 1 advantage to having a hemp building is probably the indoor air quality for the occupants," he said.

"It regulates humidity. There's no mould that can grow," he said.

"It's very warm in winter and it's cooler in the summertime — it's basically just an ideal building material for interior comfort and air quality."

"This works really well in hot climates, without the need for air conditioning, and same in cold environments."

The company's hemp blocks are also fire-resistant, Radford says, before pulling out a blowtorch and demonstrating by holding the flame to some hempcrete.

"It does not burn," he said. "It does not contribute to the flame. No smoke. No flame spread. And if you feel the back of the material, as you can tell, there's no thermal transfer. It's very insulated and fire resistant."

What that means, he added, "is that the firefighter going in to a building that's been on fire — it's still safe. You still have structural integrity of the entire building."

What's the catch? You can't use them below grade (underground). The company offers an alternative for below-grade purposes.

Terry Radford, the CEO of Just BioFiber, says his Airdrie company has created a new kind of brick, made with hempcrete and lime. (Monty Kruger)

Building process

In the past, Radford says, hempcrete blocks slowed the building process because it needed time to dry out.

"We've developed a manufacturing process where we can get our blocks manufactured on the truck within four days of production," he said.

"It's a much faster process, and when it arrives at the job site, once they're stacked up, you can start applying finishes to the interior and the exterior," he said.

"So it's quicker build times — and [also] you don't have a requirement for high-skilled labour to build them, either."

Price-wise, Radford says, the hempcrete-and-lime bricks are competitive with traditional materials.

"Right now, our cost and speed is about the same as building with stick frame," he said, "but we're a little more expensive than stick frames currently.

"We're about the same as insulated concrete form, but we're much faster. We're about half of the build time of insulated concrete form because there's no steel, no rebar and no concrete, so you don't have to wait for that to set up.

"Again, as soon as the wall is built, you can start putting your floor or your trusses on top of the wall and keep building. So there's no interruptions to build time."

Hemp is booming

Just BioFiber creates heat-resistant, carbon-negative building materials. (Monty Kruger CBC)

As far as supply goes, Alberta is hemp heaven, Radford says.

"There's a large amount of hemp being grown, and the Alberta government has been helpful to us," he said, adding that easy access to lime from Exshaw makes the province a good fit for his firm.

It turns out that hemp is a growth crop right across the country, he says.

"That number keeps increasing every year, as hemp becomes more and more popular as a crop with the growers — not only for the fibre, the part that we use, but also for grain and for cannabinoids," he said.

"Those are the real drivers in the marketplace right now, with Canadian farmers — hemp grain, hemp seed — and now with newfound uses for cannabinoids, that becomes the next high value use for hemp."

Radford says the combination of hempcrete and lime is extremely heat resilient. (Monty Kruger/CBC)


Stephen Hunt

Digital Writer

Stephen Hunt is a digital writer at the CBC in Calgary. Email:

Monty Kruger, CBC