Building with hempcrete

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begreen

Mooderator
Staff member
Nov 18, 2005
88,230
South Puget Sound, WA
This material has been popular in Europe, but it is just showing up in North America. It has a number of desirable and practical properties that makes it attractive for building. Hempcrete is lightweight, durable, a good insulator, and easy to work with. Now, with lumber prices going literally through the roof, it is getting a hard look. Watch the video on the Harmless house to learn more about this material and a very cool house too.

 
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SpaceBus

Minister of Fire
Nov 18, 2018
5,948
Downeast Maine
I've been hoping an air or hemp -crete precast product would become available in this country for quite some time. Oddly enough I see more alternative concrete materials used in Eastern Europe than I do in areas with low timber growth.
 

peakbagger

Minister of Fire
Jul 11, 2008
6,350
Northern NH
The adobe blocks have promise but I am unsure if the lime based blocks will be a winner. Lime is incredibly energy intensive product. My "bet" is on this product https://golab.us/products/ combined with the new laminated wood structural beams.
 

qwee

Burning Hunk
Jan 17, 2013
114
Idaho
I would give them a try. They are interlocking like insulated concrete forms (styrofoam blocks). But they aren't rated for load bearing so some sort of internal support required.

I tried a similar product years ago called papercrete. Papercrete is a mixture of paper, sand and cement. So paper instead of hemp. I built a tow mixer, which is a livestock tank with a lawnmower blade bolted to upright turned differential. So when it is pulled a great mixing force occurs. It worked (surprisingly). But don't expect to get more than one season from the differential - water works its way in and ruins it.

I would set up forms (4' x 8') around rebar, add water to tank, throw in newspaper, tow a little to pulp up paper, add 3 or 4 buckets of sand, add a bag of cement, and than tow again. After 5 minutes I would have an oatmeal like substance. I would bucket it into the forms. It would set up in a day. I built a little structure. The walls are a bit less than a foot thick.



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begreen

Mooderator
Staff member
Nov 18, 2005
88,230
South Puget Sound, WA
I would give them a try. They are interlocking like insulated concrete forms (styrofoam blocks). But they aren't rated for load bearing so some sort of internal support required.
They can be load-bearing I think if they have an internal structural frame. JustBioFiber makes them that way. Watch the video.
 

qwee

Burning Hunk
Jan 17, 2013
114
Idaho
I watched the entire video, and the harmless house does have load bearing hemp blocks - using a plastic skeleton. I hope this takes off in the USA and Canada - like the Tesla of house building. Heating/cooling one of these houses would be pretty easy. It is so different from how most house builders think about building.
 

begreen

Mooderator
Staff member
Nov 18, 2005
88,230
South Puget Sound, WA
I like the house's energy efficiency, rainwater collection and grid independence. You can tell its owner is an engineer.
 

ABMax24

Minister of Fire
That house is pretty impressive, so are the blocks. From what I can find they are R32+ for insulation value on the wall blocks and R70+ on the foundation blocks, which makes them suitable for northern climates like mine.

Hopefully they can find significant financial backing to bring this to mass production faster, I think there is significant demand for a product like this.

After reading more this company is based out of Airdrie, Alberta, which is only a 6 hour drive from me, practically next door by Northern Canadian standards.
 

andym

Feeling the Heat
Feb 6, 2020
424
Hicksville, Ohio
Like gigantic Legos. Cool. That home is way out of most people's price range though. The video seems to be marketing a lifestyle more than a product.
I agree however that it does seem to be a good idea. Having to build around the wires and plumbing seems like it could be an issue though. What would be involved in remodeling such a house?
 

begreen

Mooderator
Staff member
Nov 18, 2005
88,230
South Puget Sound, WA
Yes, this is a showcase. The owner is an engineer. He designed their retirement home. Living remotely on a mountain is also not for everyone. However, the principle of the product would also work for a basic 1000 sq ft house too. On a large scale, this could be used to create some affordable housing communities with low maintenance and heating costs.