Hemp building products may soon go mainstream. Here’s why your next home should be made with pot.
No, you can’t saw off a chunk and smoke it.
But if you live in a house made with hemp building products, you may trim your utility bills, have more leisure time, and be safer and more comfortable.
Industrial hemp, the non-stoney relative of its more famous cousin, marijuana, is making its way into the building products marketplace.
A recently signed federal farm bill has made hemp cultivation legal again. That means research can kick into high gear — likely leading to new hemp products for siding, roofing, drywall, and flooring.
What’s So Great About Hemp?
Hemp products — from insulation to particleboard — are non-toxic and resistant to mildew, pests, and fire, making them good choices for green home construction and remodeling. Plus, they don’t off any VOCs.
Several U.S. states have homes with hemp products, but most are in Australia, Europe, and New Zealand.
Why is it green?
Related: 8 Tips to Make Your Remodel Healthier and More Energy-Efficient
What Products Are Available Now
Previously hemp was illegal to farm here, but legal to import from other countries. That hiked up the price of what would otherwise be a relatively inexpensive material. Those prices should come down as domestic products move into the marketplace.
Currently available:
Hempcrete: Generic term for a concrete-like material made from imported hemp fibers mixed with lime.
Cost: A 33-lb. bag is $30 and makes about 5 cubic feet of wall (about 5 sq. ft. of surface area for a 12-inch-thick hempcrete wall) with an insulating factor of R-25 — higher than a regular 3.5-inch stud wall insulated with fiberglass (R-13).
Hemp board: Generic term for material that can be used in place of plywood and particleboard for wall sheathing and green cabinet construction.
Cost: 4-foot-by-8-foot sheet of half-inch-thick hemp board, $40; regular particleboard, $20
Hemp Shield: Brand name for an exterior finish for wood decks, siding, planters, fences, and play structures. In professional independent testing, Hemp Shield outperformed other well-known wood finish products.
Cost: $41/gallon, which covers about 450 sq. ft.; tinted versions are $45/gallon
Hemp insulation: Soft, woven material made from hemp fibers.
Cost: About $2.75/sq. ft.; fiberglass batts of comparable thickness and insulating value are only about 30 cents/sq. ft.