How Can Hemp Help Sick Building Syndrome?

Building materialsenvironmental buildinghemp limehempcrete

Oct 23

Written By Jean Lotus

Global Fiber Processing

Americhanvre

Hemp Build Network

Texas Healthy Homes

South Bend Industrial Hemp

Endeavour Centre

Saoirse Learning Center

Hemp Building Company

By Global Hemp Association

We spend almost 90% of our time indoors so it’s important to have toxin-free healthy air. Sick Building Syndrome (SBS) is the result of air-tight buildings with poor air circulation.

Wrapping our houses in plastic air and vapor barriers traps moisture and pollutants inside the structure.

Not everyone will suffer from SBS, but for the elderly, children, and those who already suffer from an illness that air-tight building can pose serious health risks. The symptoms usually associated with SBS are headaches, nausea, eye and throat irritation, and difficulty focusing.

There are many sources of indoor pollution: cleaning products, off-gassing from interior objects (especially plastics), and mold spores from moisture trapped in the building.

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Our buildings need to breathe to release pollutants and moisture from the interior to the outside environment. That can be accomplished without sacrificing winter warmth or summer coolness. Using hemp as a building material reduces the need to “air out” our homes in the spring.

How is Hemp Wall Construction Different from Conventional Construction?

There are a number of different fabrication methods for hemp walls. They’re made of hemp hurd, the inner woody core of the hemp stalks, lime, and water. The mix, called hempcrete, is a thick chunky slurry that can be poured into a wooden framework at a factory, formed into blocks, or mixed and applied with a blown or tamped process on-site.

Hempcrete walls are denser and thicker than conventional walls. According to the U.S. Department of Energy, hemp’s R-value is similar to other conventional insulation at about R-3.5 per inch. Hemp walls are 9-12” thick for thermal mass. When a hempcrete wall is completely dry it acts like rock and stores heat acquired throughout the day and passively releases it when the air cools.

Related: Hemp and Lime: A Compelling Choice by Alison Mears, Parsons New School Healthy Materials Lab