The new year is expected to bring fundamental advances that could help hempcrete building go more mainstream, according to a yearend summary and outlook by the U.S. Hemp Building Association (USHBA).
“With building code standardization, easy specifying in commercial structures and material standards for hemp, the year 2024 will be a groundbreaking year . . . to remove challenges for hemp-lime building materials in the U.S. marketplace,” the Association said.
The first major advancement is the inclusion of hempcrete as an approved building material for residential structures under the International Code Council (ICC). The ICC accepted an appendix governing the use of hemp-lime mixtures as a non-load-bearing building material and wall infill system into next year’s International Residential Code (IRC) update. The hempcrete provision takes effect this year.
The development is an important step to making hempcrete an option for widespread adoption in the construction industry because it gives building professionals a guide to what is required to build with hempcrete.
The ICC’s codes, introduced every two years in a staggered schedule, are primarily used in the United States, but some other countries also adopt them. The guidelines are founded on broad principles that make both new materials and new building designs possible.
In jurisdictions where local building authorities adopt the IRC standards, architects and builders can specify the material in building permit applications for one- and two-family dwellings and townhouses.
USHBA said 2024 will see work begin aimed at getting hempcrete accepted as a standard infill insulation in large commercial projects under ICC’s International Building Code, standards which are similar to but separate from the residential code, set to be updated in 2025.
In the meantime, USHBA is set to release a guide to specifications for hempcrete’s use in commercial buildings soon. The guide will give architects boilerplate language to insert into bid documents, the Association said.
USHBA said it will also develop a hemp hurd testing procedure and standards for processors to manufacture consistent building-grade hurd. In addition to giving production guidance to processors, the standards will eliminate risks to builders by ensuring the materials are suitable for construction projects.
The Association said its guidelines are intended to be temporary until the American Society for Testing and Materials (ASTM) works out standards for hemp in building materials.
USHBA said tests planned at North Dakota State and Oregon State universities will help set the bar for processors to meet building-grade quality standards for hurd based on size, levels of dust and fiber content, according to the Association. Hurd that meets the standards can be marketed as USHBA-approved.