As manufacturers advance their technology, more companies are taking strides toward making sustainable building materials. Out of all the new eco-friendly options, hemp insulation is one of the most popular. It checks the sustainability box, but it’s also an impressive insulation material in its own right, making hemp insulation equally environmentally conscious and practical.
If you’re curious about how hemp insulation stacks up against the competition, you’re not alone. Read on to learn the ins and outs of hemp insulation, compare it to other popular insulation materials, and figure out if it’s the right choice for your home.
What Is Hemp Insulation?
Hemp insulation is a natural, plant-based insulation material that manufacturers source from industrial hemp fibers. Unlike marijuana, industrial hemp has negligible amounts of THC (less than 0. 3%).
Instead, farmers grow it for its versatile fibers and seeds. Hemp insulation usually contains roughly 90% hemp fibers, with the remaining percentage being polyester fibers and non-toxic bonding agents.
How Do Manufacturers Make Hemp Insulation?
Manufacturers make hemp insulation by processing hemp stalks into fibers, which they then form into batts or rolls. The process is relatively simple, but it’s also environmentally friendly. It requires minimal energy and produces little waste. After all the processing, the hemp turns into a thick, compressible insulation material that resembles wool or cotton.
Not only is the hemp insulation product more eco-friendly than traditional insulation materials, but the manufacturing process is too.
Availability and Legal Status
While hemp cultivation was previously illegal in the United States, those days are long gone. The United States Department of Agriculture passed a bill in 2018 allowing states to make their own legislation for industrial hemp cultivation. As a result, hemp insulation is becoming more readily available throughout the country.
Ecological Benefits of Hemp Insulation
Hemp insulation has more environmental advantages than its competition, including the perks below:
Sustainable Crop Production
Hemp is a fast-growing, low-maintenance crop that requires minimal water and no pesticides or herbicides to thrive. As a cover crop, hemp helps improve soil health by shading out weeds and adding nutrients to the soil. Its deep taproot system also helps loosen compact soil and improve water retention.
Carbon Sequestration
Hemp plants are excellent at absorbing carbon dioxide from the atmosphere. During its growth cycle, hemp absorbs more carbon dioxide than it releases, making it a carbon-negative crop. This means that hemp insulation can also help reduce greenhouse gasses in your home.
Recyclability and Biodegradability
Hemp insulation is easy to recycle or compost, unlike many synthetic insulation materials. This means that you won’t contribute to landfill waste, making it even more appealing for homeowners who care about the environment.
Hemp Insulation Performance
Hemp insulation isn’t just a tree-hugger’s dream; it also delivers impressive performance. Here are a few areas where hemp excels:
R-Value and Thermal Performance
Hemp insulation boasts an R-value of approximately 3.5 per inch of thickness, which is similar to other leading insulation materials. You can also compress hemp, making for higher R-values in standard wall cavities.
For example, you can install a 5.5″ piece of hemp insulation between 3.5″ studs to provide an R-value of 19.25, which is even higher than the requirements for the coldest climate zones in the United States.
To better understand insulation R-value, check out our informative guide.
Moisture Management
One of hemp insulation’s biggest perks is its moisture management properties. Hemp fibers are hygroscopic, meaning they can absorb and release moisture without compromising their insulating properties. When you use them as insulation, hemp fibers help regulate humidity levels within your home and work to cut down mold and mildew growth.
Acoustic Properties
Due to its density and thickness, hemp insulation also provides excellent sound absorption. This makes it great for homeowners who live in large cities or noisy environments.
Hemp Insulation vs. Traditional Insulation
If you’re choosing whether to buy hemp insulation, it helps to compare it to some of the most popular insulation options on the market before you make your decision. See how hemp stacks up to the competition below:
Hemp vs. Fiberglass Batts
Fiberglass batts are the most common type of insulation in residential construction. While fiberglass and hemp offer similar R-values, hemp has better moisture management, it’s biodegradable, and installation won’t leave you feeling itchy or irritated.
On the other hand, fiberglass is less expensive, which is a big plus for most homeowners. If performance or sustainability is your top priority, hemp is your best bet. If cost is your main concern, nothing beats fiberglass.
Hemp vs. Rigid Foam Board
Rigid foam board insulation offers a higher R-value per inch than hemp, which can be beneficial for temperature regulation. It also has excellent moisture resistance, making it great for rainy climates.
However, hemp insulation has better breathability and is easier to work around obstacles like pipes and electrical boxes. Plus, since you can compress hemp, you can increase its R-value as long as there’s enough thickness in your walls to press it down.
Hemp vs. Spray Foam Insulation
Spray foam insulation creates an airtight seal and offers higher R-values, especially closed-cell foam. However, hemp insulation doesn’t have any harmful chemicals during insulation and offers better breathability, which can prevent moisture buildup. Performance-wise, this match-up is a bit of a toss-up, but hemp’s environmental perks give it an edge over the competition.
Cost Considerations
Hemp insulation typically costs more than traditional fiberglass batts. According to Angi, hemp insulation costs between $1.40 and $3.10 per square foot, compared to $0.30 to $1.50 per square foot for fiberglass, though prices should decrease as hemp insulation becomes more widely available.
