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Building to Code with Hemp-Lime (Hempcrete)

Here is a great reference document that defines and illustrates standards for building with hempcrete as it relates to the residential building code.

https://hempandblock.com/wp-content/uploads/2023/09/Hemp-Lime-IRC-Index-2-1.pdf

You can find other ICC supporting documents for hempcrete construction on the US Hemp Building Association website.

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Where do your “sustainable” hemp building materials come from?

Health risks of shipping pollution have been ‘underestimated’

This article is more than 14 years old

One giant container ship can emit almost the same amount of cancer and asthma-causing chemicals as 50m cars, study finds

https://www.theguardian.com/environment/2009/apr/09/shipping-pollution

I read the article and was shocked! While I had the feeling it was bad, had no idea it was that bad. Here are some initial thoughts I shared on Hemp and Block’s Instagram. We are working daily, doing our part to make hemp building materials that are #1 actually Made in USA and #2 truly “green” and sustainable!

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Hempy Mortar to Reduce Cold-Bridging of Hemp Blocks

Hempy mortar is insulating which helps reduce heating and cooling costs. Featured on Hemp and Block’s Instagram 7/12/2023.

Prototype pics for what I’m calling “Hempy Mortar!”

How about using hemp and other insulating aggregate to create load bearing mortar (similar to a “Type N” mortar for above-grade masonry) with R value?? Yes I’m talking about eliminating any potential cold bridging that may happen with conventional cement:sand mortar.

How to make insulating hempy mortar

Here’s a mix design for hempy mortar that works great with hempcrete (hemp-lime) building. Just 3 ingredients:

  1. Our hempcrete binder
  2. Small pumice stones (ideally 1/4″ … 3/8″ tops)
  3. Hemp hurd fines (these are 1/4″ – 1/8″)

The pumice is used in place of sand to bring R value (insulation benefit) and compressive strength. Hemp hurd fines work real well as an insulating, “fine aggregate” that pairs well with the small pumice stones. Together, the hemp fines and pumice stones fill up the void space in the manner required when combining course and fine aggregates in a mix.

An example of a hempy mortar mix ratio by volume:

  • 1 part Hemp and Block hempcrete binder
  • 1 part insulating aggregate (such as small pumice stones)
  • 1 part hemp hurd fines
  • Enough water to make a workable mortar. Stiff enough that if you flick your trowel and turn it upside down, the mortar sticks to the trowel. Too soupy = weak mortar. Too dry = not workable enough.

Be sure to wear appropriate personal protective equipment when working with hydrated lime, cements, et cetera. Goggles, gloves, dusk mask and protective clothing!

Also, look at the hemp lime bond strength! In the image above, the top block being held is a lighter hempcrete mix, the block weighs 10 lbs. The bottom hemp block is denser and heavier at 25 lbs. Our Made in USA hempcrete binder is a proprietary blend of hydrated lime, natural pozzolan, and other minerals to make hemp blocks, hempcrete walls, floors and more. The time-tested combination of hydrated lime and pozzolans allows for masonry mortars that really stick when you need them to!

And being a big supporter of local economy…

You can also use foamed glass aggregate or similar instead of pumice if it’s closer to you. Pumice has many benefits and very eco-friendly… but I also use it because it’s within my region. If foamed glass or expanded clay are the only options near you, you can still make hempy mortar. This industry needs to stay evergreen and sustainable! That means buying local as possible.

Have any questions about hempy mortar and other hemp-lime building materials? Feel free to contact Hemp and Block anytime.

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Hempcrete Bakery Build – Part 2

The Hempcrete Bakery Build! Follow along with Derek, Founder and CEO of Hemp and Block LLC, as we work on another exciting hemp building project. This may be another “World’s First!” that we are proud to share. Located in Colorado, this old, run-down shop is being renovated into a hempcrete bakery!

Part 1 was filmed early May and this update is from mid-June. I discuss cure times, what does fresh hempcrete smell like, finishing of hempcrete walls, pros and cons of pre-cast vs cast-in-place, benefits of placing hempcrete walls against summer sun, temperature differences after casting hemp-lime walls, and more!

Using a variety of cast-in-place methods, including tamping and spray (shotcrete) applications, the space will be retrofitted with hempcrete (hemp-lime) for major performance upgrades. Benefits of using hempcrete for walls, floors and ceilings:

  • long term durability and strength
  • great insulation and thermal mass, reducing cooling and heating costs -resistance to bugs, fire, mold and pests
  • walls that absorb and damper sound
  • walls that “breathe” (vapor permeable but water-tight), helping to manage humidity, air quality and comfort
  • a natural alternative to conventional, toxic construction materials
  • a sustainable healthy home or building that is carbon friendly; carbon sequestering even, as hemp pulls in CO2 during its growth cycle and hempcrete draws in even more CO2 from the air as it cures and hardens

For this build, we are using our proprietary hempcrete binder and processed American hemp hurd. Our hempcrete binder is proudly 100% Made in USA with domestically sourced ingredients. It can be used for mixing hempcrete, as a plaster or render, or a mortar, depending on mix design.

For example, a mix ratio for mortar by volume: 1 part binder, 2 parts clean sharp sand, just enough water to make a stiff mortar…

And for the hempcrete mix ratio, on this build for walls we did 1.5 parts binder to 3 parts hemp hurd. 1:3 works real well for typical walls but in this bakery (fire risk!) the extra binder makes for an even denser and tougher wall. Still quite hempy. May use the lighter 1:3 mix on upper level of wall (9′ and above to the vaulted ceiling).


About Hemp and Block LLC: Proud to be Colorado’s First Hempcrete Block Company as of 2018. Nearly America’s first… but perhaps the longest running American producer of hemp blocks? We are working every day to get hemp building into the hearts and minds of more and more people.

Unlike most hemp blocks on the market, which are imported from overseas and burn up lots of fuel crossing the ocean, our hemp blocks are cast and cured in the USA. Also, our building materials such as our proprietary hempcrete binder is 100% made in USA. Did you know that most hempcrete/lime binders are imported, too? We also only use American grown hemp!

Hemp and Block LLC makes these choices to help support and create more jobs and businesses for Americans. Supporting local farms, economies and supply chains as best we can! Every hemp block we cast or for every hemp wall put up, we are putting dollars into pockets of our friends and neighbors throughout our region.

A little more about our operation… Our hemp building products are manufactured in a quality controlled environment with strict requirements for raw materials, production and curing. Consistent quality, assured.

Family owned and operated in the USA since 2018!

And eager to innovate… Colorado’s first hempcrete block company, creator of the World’s First hempcrete garden bench, coffee table, hemp pavers and more to come!

Be sure to join us on social media:

Instagram: @HempandBlock

YouTube: @HempandBlock

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Hempcrete Bakery Build – Part 1

The Hempcrete Bakery Build! Follow along with Derek, Founder and CEO of Hemp and Block LLC, as we work on another exciting hemp building project. This may be another “World’s First!” that we are proud to share. Located in Colorado, this old, run-down shop is being renovated into a hempcrete bakery!

Using a variety of cast-in-place methods, including tamping and spray (shotcrete) applications, the space will be retrofitted with hempcrete (hemp-lime) for major performance upgrades. Benefits of using hempcrete for walls, floors and ceilings:

  • long term durability and strength
  • great insulation and thermal mass, reducing cooling and heating costs -resistance to bugs, fire, mold and pests
  • walls that absorb and damper sound
  • walls that “breathe” (vapor permeable but water-tight), helping to manage humidity, air quality and comfort
  • a natural alternative to conventional, toxic construction materials
  • a sustainable healthy home or building that is carbon friendly; carbon sequestering even, as hemp pulls in CO2 during its growth cycle and hempcrete draws in even more CO2 from the air as it cures and hardens

For this build, we are using our proprietary hempcrete binder and processed American hemp hurd. Our hempcrete binder is proudly 100% Made in USA with domestically sourced ingredients. It can be used for mixing hempcrete, as a plaster or render, or a mortar, depending on mix design.

For example, a mix ratio for mortar by volume: 1 part binder, 2 parts clean sharp sand, just enough water to make a stiff mortar…

And for the hempcrete mix ratio, on this build for walls we did 1.5 parts binder to 3 parts hemp hurd. 1:3 works real well for typical walls but in this bakery (fire risk!) the extra binder makes for an even denser and tougher wall. Still quite hempy. May use the lighter 1:3 mix on upper level of wall (9′ and above to the vaulted ceiling).


About Hemp and Block LLC: Proud to be Colorado’s First Hempcrete Block Company as of 2018. Nearly America’s first… but perhaps the longest running American producer of hemp blocks? We are working every day to get hemp building into the hearts and minds of more and more people.

Unlike most hemp blocks on the market, which are imported from overseas and burn up lots of fuel crossing the ocean, our hemp blocks are cast and cured in the USA. Also, our building materials such as our proprietary hempcrete binder is 100% made in USA. Did you know that most hempcrete/lime binders are imported, too? We also only use American grown hemp!

Hemp and Block LLC makes these choices to help support and create more jobs and businesses for Americans. Supporting local farms, economies and supply chains as best we can! Every hemp block we cast or for every hemp wall put up, we are putting dollars into pockets of our friends and neighbors throughout our region.

A little more about our operation… Our hemp building products are manufactured in a quality controlled environment with strict requirements for raw materials, production and curing. Consistent quality, assured.

Family owned and operated in the USA since 2018!

And eager to innovate… Colorado’s first hempcrete block company, creator of the World’s First hempcrete garden bench, coffee table, hemp pavers and more to come!

Be sure to join us on social media:

Instagram: @HempandBlock

YouTube: @HempandBlock

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Made in USA Hempcrete, Hemp Blocks and More

So where do you guys get your hemp??

I write this article just days after exhibiting at a local Home Show Expo. I couldn’t have imagined a greater reception from our community! Some knew of hempcrete and were excited to see a Colorado company doing big things with it. Others hadn’t even heard of hempcrete before, let alone seen it or picked it up, and they were so happy to learn about it.

And in both cases, people were very interested to know where we source our hemp.

It makes me tremendously proud to say that our hemp is grown and processed right here on American soil. Above that, we source as close to home as possible.

As proud members of the US Hemp Building Association, we source hemp from within our Region #4 that includes Colorado, Nebraska, Kansas, Utah, Arizona and New Mexico.

Why buy American hemp? Why is Made in USA for hemp blocks so important?

The industrial hemp industry has the potential to deliver high quality, sustainable products that are made in the USA. All those products will be made by Americans, supporting local economies. And the hemp should be grown and processed in the USA as well.

Made in USA is a big part of our commitment to quality and sustainability.

Hemp and Block proudly offers made in USA hempcrete, hemp blocks, pre-cast hemp-lime products, hempcrete binder and more.

To support the American economy and help grow US infrastructure, all raw materials including hemp, mineral binders and pozzolans, aggregate – all sourced from within the USA.

Rather than importing, say, hemp hurd from China and lime from Europe, which burns tons of fuel to cross the ocean… and syphons dollars from Americans… we are doing our part to make American hempcrete very sustainable and very rewarding to fellow Americans.

Since 2018, Hemp and Block LLC has been the hemp block company that’s actually made in USA! Our hempcrete and hemp blocks are cast and cured in beautiful Colorado, USA.

With those commitments, we can fulfill the legal definition of Made in USA, as regulated by the Federal Trade Commission. That also means when you build with our hemp blocks or hempcrete mixes, you can say “Made in USA” on your project as well!

And somewhere out there, an American hemp farmer gets the boost they need to continue forging ahead in this frontier. A processing facility gets the financial incentive they need to keep their machines running. All throughout that supply chain and distribution network, from farmer to end user, together we are making America more sustainable, healthier, happier and more prosperous.

Sincerely,

Derek Wolf, Founder and CEO, Hemp and Block LLC

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How Hempcrete can Relieve the Portland Cement Shortages

Have you heard? There’s a shortage of Portland cement that (almost) no one is talking about. It’s gotten bad enough that contractors are delaying jobs and weighing lay-offs.

The good news, is that hempcrete (or hemp-lime) construction is a highly sustainable alternative that can help relieve the shortages.

Portland cement: always there… until it’s not

There are certain things I’ve grown accustomed to while living in our modern age. Flip a switch and the lights come on. Go to the grocery store, see shelves full of food. Go to the [Big Box Home Improvement Store] and see dozens of bags of Portland cement.

As you may already know, Portland cement is the gray powder that when mixed with water, becomes the pasty glue of modern concrete. The other key ingredients are sand and gravel.

And as long as I’ve walked this great plane, Portland cement is always available at the store.

But what happens when it’s just not there…?

As you and I experienced during the Covid pandemic, it is entirely possible for the supply chain to stall or outright collapse. This was demonstrated by the widely reported, barren grocery shelves. Who expects that grocery stores just won’t have food? Or what they have is so tightly rationed…

As I write this in September of 2022, I can say that by late spring/early summer, I noticed that my local Home Improvement store seemed to be running awfully low on Portland cement.

First, the big 92.6 lb. bags were gone. And there were only a handful of the 47 lb. bags left. (The big bags cost lest, per lb.)

Next time I happened to be in the store, I checked out of curiosity and there was no Portland cement at all! This continued for several months.

And then a good friend of mine, who uses a lot of Portland cement for building and heavy duty drilling, said he’s been backordered with [The Popular Brand of Bagged Cements You Always See at the Depot] for weeks and weeks. He needs multiple pallets at a time, he’s paid for it, but can’t get it. He’s had to put jobs on hold and finally had to drive the next state over to pick it up from the cement plant.

I wondered if this was just an issue in my rural Colorado town, or something bigger? Here’s what I found…

Labor and cement shortage causing ‘perfect storm,’ industry expert warns

Demand for construction is ‘crazy,’ Metrocon, Inc. president said

Concrete company president on how labor, cement shortage impacts industry

Metrocon, Inc. President Dan Crosby warns that the labor and cement shortage is causing the ‘perfect storm’ in the industry.

Metrocon, Inc., is based in South Carolina and prides itself on premier ready-mix concrete. Crosby stressed that his business is only taking on 60% of the work that it can normally handle amid the labor and supply shortage. 

https://www.foxbusiness.com/economy/labor-cement-shortage-industry-leader-economy

The few other articles I found had more of the same story. Surprisingly, the Portland cement shortages extend all the way into Canada!

Cement shortages are putting pressure on Canada’s construction industry

Uncertain supply means hard choices for builders, even as the sector enjoys a boom year. Emad Sleiman, the owner of Apex Concrete, says the cement shortage has his business scrambling to schedule concrete for their contracts. (Justin Pennell/CBC News)

Apex used to schedule concrete trucks based on the projects they had coming up. Now, they’re booking any available concrete and trying to squeeze clients into those days. Some jobs are being pushed back weeks as they wait for materials and other Calgary companies, like Omega 2000 Cribbing Inc., are turning clients away. 

“I don’t know how other contractors are going to survive. I don’t know how the suppliers [are] going to keep providing,” said Sleiman.

The construction sector is having a boom year, as consumers and companies pour more dollars into building infrastructure. But cement, a key ingredient in making concrete, has become scarce, and the shortage — caused by a confluence of increased demand, labour shortages, inflation and issues at major plants — is creating serious problems for the construction industry across the country. […]

https://www.cbc.ca/news/canada/calgary/cement-concrete-shortage-construction-canada-von-scheel-1.6522155

I then called up the big name-brand cement company who supplies the stores and normally sells Portland in bulk. They literally told me that they can’t even take my order!

The cement shortage is so bad, they’ve had customers who are on “allocation” for a certain volume are having trouble getting all their material on time.

After a bit digging on the internet, I found several cement plants and terminals within my state. They were having the same troubles, although one offered bulk tanker orders (I’d need a large cement silo on-site to receive the delivery). Basically, bagged Portland cement was a no-go except for what you could scavenge (fight for?) at the store.

Portland cement gets a lot of heat for its environmental footprint, as global production is responsible for at least 8% of total global CO2 emissions. Last I’ve heard, to alleviate shortages in the US, Portland cement is being imported by truck and freighter ship. What’s the footprint on that?

How Hempcrete can help relieve Portland cement shortages, globally

Hempcrete, a form of hemp-lime construction, offers a sustainable alternative to Portland cement-based concrete.

In a broader scope, hemp-lime involves any use of hemp and a lime-based binder or mortar for building. It is masonry in the vintage and historic sense, as an extension of the lime (limestone, quicklime, slaked… etc.) construction methods dating back to the Romans and ancient Greeks.

The definition of hempcrete emphasizes use as a self-insulating, non-structural, thermal mass for walls, floors and more. Hempcrete is being recognized and celebrated for being resistant to fire, mold, pests, it “breathes” to improve air quality and reduce dampness buildup within walls and homes, gives acoustic benefits to walls, has autogenous healing properties and more. There’s also a great deal of exciting research about the performance benefits of “fiber reinforced concrete,” to which hempcrete shares.

Although Portland cement-based concrete is more appropriate for below grade applications such as foundations, hemp-lime methods have great use above ground level. And while “hempcrete” is most often designed to be light and insulating, I’ve mixed and cast hemp-lime masonry products that are hard as stone.

This includes blocks, pavers and garden benches that I weathered outside 24/7 uncovered, unfinished (no lime render etc.), through Colorado rain, snow and sunshine for 3 years before ever discussing them with the public.

Depending on project goals and preferences, hempcrete can be made with more or less Portland cement. Or no Portland cement at all. Portland gives a strong and fast hydraulic set to concrete or hempcrete, meaning it cures through hydration and can even cure under water. However, those benefits come with drawbacks, including Portland cement creating masonry that can be brittle, inflexible, overly reactive with chemical salts and even steel rebar causing early failure… and then there are the environmental concerns.

Lime-based binders and mortars typically take longer to set, cure and gain compressive strength, but carry long term benefits of strength and longevity. See, Roman Concrete and The Pantheon. The world’s largest unreinforced concrete dome, still standing after approximately 2,000 years! They accomplished that without Portland cement or steel rebar.

The lime-based binder is what allows hempcrete walls to breathe, self heal, and more. Although Portland cement could be used (and from what I’ve seen, often is used) for hempcrete, it can impede the benefits of using lime, creating a less flexible, less breathable, perhaps shorter lived building or home. Using a small amount in the binder may give the benefit of quicker and more hydraulic sets, but that is up to the builder, contractor or homeowner and their preferences.

So whether someone uses some Portland or no Portland in their hempcrete project, there is a lot of value in at least replacing a portion of Portland cement with more sustainable and more readily available alternative materials. Each ton of Portland cement that is not used can prevent 1 ton of CO2 being released.

Certain types of lime are more hydraulic than others. And then there is the topic of pozzolans. Such as volcanic ash, that when in small, divided form and mixed with hydrated lime and water forms cementitious compounds . I was truly fascinated to discover the accomplishments of Roman engineers and masons, who built massive structures that were beautiful, functional and withstood the sands of time.

I carried that wisdom forward when formulating the proprietary and exclusive mix designs for Hemp and Block, LLC. By utilizing lime and pozzolanic materials, you can build as needed without being so reliant on a single product such as Portland cement, which may or may not be available when you actually need it. The raw materials are available in abundance, so I acquire those in bulk and cast hempcrete as needed.

Pre-cast hempcrete blocks for building walls also offer you convenience on bigger jobs. Rather than having to rely on Portland-cement based concrete the day of the job, you can have cured hempcrete blocks delivered to the job-site and build as fast as you want.

Portland cement definitely has its purpose, but the Portland Cement shortage of 2022 is another great example of why we constantly explore and develop sensible and sustainable natural building methods. Hemp-lime and hempcrete have a bright future in this space.

Derek Wolf, CEO, Hemp and Block, LLC.