As Lumber Prices Surge, Hemp Blocks Get a Closer Look

[Jean Lotus]

The cost of U.S. construction timber is skyrocketing, and a national concern is growing for the carbon emitted by the construction industry. As homebuilders look for solutions, the nation’s small-but-growing number of hemp builders wonder if building with hemp will finally break through into the mainstream construction consciousness.

The cost of framing lumber, OSB plywood and other wood building materials are adding an average of $36,000 to the cost of a new build, an April study showed -- and costs have kept rising.

As a result, homebuilding solutions that don’t require framing timber, or need less of it, are getting a second look. One solution is the hemp-lime block.

The U.S. construction industry is notoriously resistant to change and innovation, frustrating those who want to introduce hemp building to the United States, as it has been used for the past 30 years in Europe.

But ‘hempcrete’ blocks are being noticed because they have been used in European builds for decades, and provide a green, carbon-sequestering, insulative wall solution.

“We have been working to decarbonize the construction sector for 10 years now and we remain 100% convinced that the hemp block has a crucial role to play,” Charlotte De Bellefroid, spokesperson for Belgium-based IsoHemp, wrote in an email to Hemp Build Mag.

Precast hemp blocks, made with chopped hemp hurd and lime binder are much lighter than concrete blocks. The blocks can be quickly assembled and provide insulation rates up to R70. Uniform-density blocks are easy to transport to a worksite, and are pre-cured, saving drying time compared to hand-cast “in situ” or spray applied hempcrete construction.

Walls made with hempcrete blocks are fireproof, mold proof, pest proof and long-lasting compared to timber-framed homes, which can be constructed of poor quality materials.

READ MORE at HempbuildMag.com

[Jean Lotus]

How are they different from cinder blocks? Insulation properties. Whereas concrete conducts heat, the hemp blocks have air pockets that regulate the temperature. They are also lighter than concrete. In fact one person can carry a stack of 10 JustBioFiber blocks.

How do we know it won't decompose? There are department stores and multistory apartment buildings in Europe built with hempcrete 30 years ago that are going strong. Also there are 6th-Century bridges in France built with hempcrete that are still standing. 

How do you run the electrical? Some block systems have holes for conduits. Other systems cut channels in the hempcrete with a chainsaw and then cover. See video here: