Hemp Hurd Source

ARIZONA... Anyone finding Hemp Hurd is plentiful, buy you can't seem to find any???  
Sourcing it from other states seems expensive.  
What experiences are you having try to use this abundant, cheap, wonderful rescource?

What is that product?

They might be growing hemp in your state but varieties for seed and oil ,so unless the variety used preferably for the outer fiber on the stalk is being processed for its outer fiber layer ,you wont have the byproduct available which is the inner part called hurds , on the market for sale.

Hi Dean,
I too have found it expensive to source. I would like to try some hempcrete projects, but there is no close source. I wanted to try a small plot here to see how it grew. While it is legal in Maine, I think they thought I was going to try to grow a variety for... other reasons than just fiber. It was going to be more trouble than it was worth, so I started looking around, and there are not many places that sell the hurd or shiv.

perhaps if you make contact with the horse racing/breeding sector or farms in your area ,they might pass on the contacts they have for buying hemp shiv/hurd, as its a popular bedding material for them ,and be prepared to buy in bulk like they would.

John C Daley wrote:What is that product?

Hemp herd is the fibrous inner core of the hemp stalk, broken into bits.  It has amazing insulative properties for building homes and has the highest R-value of any building insulation known to man.  It is also used for animal bedding, garden mulch, etc.  Look up Hempcrete and be amazed as you take it all in.  Much like strawbale construction in many respects.  It can be made into blocks for stacking thick walls, panels for insulation, is used as a free forming light-weight material for walls, infill of walls, sound proofing, it has breathability when coated with natural lime plasters and paint, it is fireproof, light weight, grown in most states, and is the byproduct of hemp raised for fiber, rope, textiles, oils, edible seeds, and more.  Hemp is the  is becoming legal in most states, though thoroughly regulated.  Enjoy.

I appreciate Dean's enthusiasm for hemp--reminds me of the early days of building with straw bales when some people proclaimed that a straw bale building could be heated with little more than a candle (if only that were true!).

There are wishes and there are facts.  Setting aside the real contribution that thermal mass can make to one's sense of comfort in a well-insulated, well massed structure, there are objective metrics for determining a material's resistance to heat flow (R-value) per given thickness.

Sadly, hemp isn't the most insulative material known to human kind.  I wish it were.  

I believe that  honor goes to a space-age material called Aerogel, with an R-value of 10.3 per inch.  It's used in the windows of space shuttles and costs a small fortune both to purchase and to manufacture, in terms of embodied energy.  

Next up are various foams.  Closed cell spray foam comes in somewhere between R-6 and R-7 per inch depending on application (the sprayers can mess things up by packing too much or too little material into a space).  Open cell foams come in between R-3.6 to R-3.9 depending on application.  Both have an embodied energy cost that far exceeds Portland cement.

Fiberglass and Rockwool (mineral wool) are reliably R-3 to R-4 per inch when installed as batts (that aren't  compressed) in wall and ceiling cavities.

Finally, we have the more natural, mostly plant-based materials.

Blown-in cellulose and chopped straw are both rated around R-3 to R-4 per inch, again depending on density.  Hemp herd is similar.

Hempcrete (hemp hurd plus lime) comes in at R-2.1 per inch so long as it's mixed and placed per the building code's density recommendation, and this is also true of light straw-clay (slip straw), which has an R-value of 1.5 to 1.85 per inch.

Straw bales, if at least 6.5 lbs./cubic foot dry density have a range of R-values depending on orientation in the wall.  Bales laid on-edge are rated at R–1.85, and bales laid-flat offer R-1.55 per inch.

Wood (think log cabin walls) is R-1 per inch, and cob is given R-.22 per inch.  Adobe is  similar to cob.

It's fair to say that of the plant-based insulation materials currently in use hemp hurd (by itself) is an outstanding insulator, right up there with blown-in cellulose (chopped up recycled paper) and blown-in straw.  As a bonus, all of the plant-based materials have a lower embodied energy than Aerogel, foam, fiberglass, or rockwool, and they also store carbon for the life of the building.

All good reasons to use plant-based materials when we build.

Jim
Many Hands Builders

Jim Reiland wrote:All good reasons to use plant-based materials when we build.

Since you're up on this, what about wool? We've got a lot of sheep farmers in my area, and I know wool is used in some places as insulation, but have you any info about small-scale processing it for insulation and what its R-value is?

Similarly, feathers are a by-product on my farm (mostly geese and duck) and I've wondered about using them to insulate a small structure. Straight feathers would settle over time, so I wondered if anyone had tried putting them in a form and spraying them with a thin glue of some sort.

Yes, neither of these are "plant based" but they're definitely a local renewable resource!

Hi Jay,

I think wool is a great choice!  I worked on a couple of projects that used wool batts for ceiling insulation.  The R-value per inch is comparable to other batt materials like mineral wool, fiberglass, and cotton.  The company I'm familiar with--Havelock--offers insulation that has been treated to prevent moths from eating the insulation, and may also retard flame--you'd have to check on that.  I don't know if feather insulation is available commercially yet, but if you research it on-line you'll see that there have been developments--someone is looking into using "waste" feathers for insulation board or blown-in.  

Both have a higher environmental impact than plant-based insulations in terms of embodied energy, but almost certainly lower than fossil fuel based insulations.

As a builder who was responsible to fix failures I was cautious about doing something experimental.  In fact, that's one of the biggest reasons we don't see more natural materials being used in construction today--builders are risk averse (as are lenders and insurance carriers) and look with some skepticism on alternative materials and methods.  

I often had to ask this question: if this doesn't work, can I afford to do it over?  Materials like straw (in the form of bales, panels, boards, loose fiber, etc.) aren't backed by powerful industry associations that fund research, development, and building code writing.  Just a handful of individuals and non-profit groups like the California Straw Building Association in the United States (other groups in Europe and elsewhere) have pushed to make materials like straw less "risky" to owner-builders, designers, building contractors, building code enforcement officials, lenders, and insurers.  Other more-natural building materials face a similar barrier on the road to gaining wider acceptance.

If I were going to use an unfamiliar or untested insulation material I'd want to monitor it until I was certain it was performing as expected, and have a plan to replace it if necessary.  Removing insulation from an attic with plenty of headroom is a production, but not nearly as complicated removing it from a sealed up wall.

Jim
Many Hands Builders

I have found hemp hurd in Idaho for a decent price

grant fullmer wrote:I have found hemp hurd in Idaho for a decent price

Guessing you’re looking at hempitecture? They also make a great hemp wool insulation I’m considering using. It does contain some plastic but is 0 VOC. Their 5.5” Hempwool insulation = R-20 and a whole heck of a lot cheaper than similar insulatory value hempcrete (which would need to be thick as heck to get to R-20.)

https://www.hempitecture.com/