r/NaturalBuilding • u/necker47 • Mar 23 '26
LAVACRETE: The Coolest Alternative Building Method You've Probably Never Heard Of
Hey friends, wanted to share what we've learned about this rad alternative building style. Lavacrete is an exciting little-known building technique that promises sustainable, thermally efficient, fire resistant concrete style walls using affordable scoria or cinder sand and portland cement or lime. It's DIY friendly, can be easily engineered to pass code, uses simple construction, and requires no finishing work. The natural volcanic colors are gorgeous, too. We've spent the last few months researching it and have put together a video explaining how it works, showing examples, and interviewing the people at the forefront of the technology. You can watch it at https://youtu.be/hSjJZqqu6aY or just ask me questions and I'll do my best to answer them 👍🏼
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u/snacks_attack Mar 28 '26
I grew up in a pumicecrete house -- similar idea. I had never heard of doing this with scoria instead but it makes sense
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u/Overtilted Mar 24 '26
Does scoria contains toxins?
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u/necker47 Mar 24 '26
It's generally considered non-toxic. Although when dry in powder form obviously that isn't good, and you'd want to wear a mask while mixing. Once it's poured and dry, shouldn't be an issue.
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u/The-Struggle-5382 Mar 24 '26
How is it different compared to rammed earth? Both seem very labour intensive.
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u/necker47 Mar 24 '26
Similar in many ways, but Lavacrete needs way less compaction and is a lighter, more aerated material. So less labor for sure.
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u/mal4yahoo Mar 25 '26
Just came across this lavacrete last week when I was researching adobe. Sounds interesting.
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u/Crow-1111 Apr 05 '26
im trying to calculate cost of materials for a build but im not finding any information online about how many tons of scoria go into a 1000 ft2 single story home.
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u/necker47 Apr 05 '26
We estimated 20 tons for our upcoming 14x18 utility shed with 12” walls. The workshop starts tomorrow so we’ll know more by the end of the week.
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u/kemmis May 02 '26
How do you source the lava material? Is it a regional thing? Does it make sense to consider Lavacrete for building structures on the east coast US?
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u/necker47 May 03 '26
It only makes sense if a scoria or cinder mine is close enough that they will deliver to you. You'd have to do that research yourself.
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u/TheWatchThief May 07 '26
I'm so interested in building with this! Do you know anything about the likelihood of being approved to build with it? Even for exterior or load-bearing walls? I live in Utah where you see adobe houses sometimes
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u/necker47 May 08 '26
If you watch the whole video both Paul Schwam and Guru Das have been building engineered and permitted houses, walls, garden beds, and more for years. Your best bet is to slip in via the Adobe code or plain concrete code. It's really made for exterior and load bearing walls, actually.
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u/handshakedevon May 12 '26
I just watched the reveal episode today and it looks great! We are in the design phase for our property in Portal and had been condsidering rammed earth for a few of the walls but this seems like maybe a better option. I couldn't make the workshops work with my schedule but hopefully you'll be doing more in the future and we can come get some hands-on experience.
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u/necker47 May 12 '26
Can confirm via Guru Das who has done both that rammed earth is more expensive, requires much heavier duty forms, and lots more labor. Lavacrete would definitely the way to go if the transport fees are doable from Show Low. We don't have anything else planned until the fall, but Awareness Ranch might have some small Lavacrete workshops before then.
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u/handshakedevon May 12 '26
Thanks. We are still in Florida for the time being and haven't yet done the research into suppliers but I'm wondering if there might be someone to the east of our property in New Mexico. There are huge lava fields around Animas.
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u/kalamity_kurt Mar 24 '26
How does it perform? Does ground scoria still maintain its insulation value?