Back in January, in response to the destruction of the Marshall Fire, I wrote about various building techniques and materials, including concrete, that could make homes more fire resistant than today’s common wood-frame tract homes.
Last week a reader shared a recent article on Treehugger.com about AirCrete, “a foamy mixture of air bubbles and cement that is cheap to make, water-resistant, fireproof, and [Do-It-Yourself]-friendly.” Here’s a link to that full article. There’s a 7-minute YouTube video within the article that describes the process.
The process is the brainchild of Hajjar Gibran, the great-nephew of the poet Kahlil Gibran. His enterprise sells the tools for creating AirCrete using locally obtained cement. The only other ingredients are water and your choice of a degreasing dish detergent to create the foam using a 120V foam injection mixer which they sell for $199 on their website, www.domegaia.com. For $95, Mr. Gibran himself will provide a professional AirCrete consultation, or, for $700 tuition, you can attend a 10-day workshop.
Although the organization is focused on building domes, it’s clear that the process can be used to build other types of structures. With total structural building costs in the $2,000 to $9,000 range, the process is marketed specifically for building “tiny homes,” and would, it seems, provide an affordable way of addressing the problem of homelessness. I’d love to see it used here in Colorado!
Regular concrete has a low R-value, the common measurement of insulation — 0.1 to 0.2 per inch of thickness. Because of the air bubbles within it, the R-value of AirCrete is 6 per inch of thickness. This is roughly twice the insulating value of a typical 2×4 wood-frame wall filled with blown-in cellulose.
As I noted in my earlier columns, the manufacture of Portland cement is a major contributor to global warming, responsible for an estimated 7% of all greenhouse gas emissions worldwide. Because AirCrete is mostly air, its use of cement is far less than an equivalent volume of traditional concrete.
According to the Treehugger.com article, “The blend creates a lightweight and low-cost building block that is fireproof, water-resistant, insect-proof, and serves to insulate the building. According to its creator, AirCrete offers many desirable attributes for use as a building material for single-story residences, especially for the owner-builder, among them the ability to cut construction costs by a factor of 10 when compared with conventional construction.”
The article continues: “Beyond its affordability, DomeGaia says their AirCrete is easy to work with, drying in just one night and flexible enough to be shaped into almost any form. You can use your standard wood-working tools to carve or drill into the material, inserting screws and nails where necessary. Since the material hardens as time passes, you can be more confident about the shape you settle on instead of being increasingly worried about future vulnerabilities.”
DomeGaia’s workshops sound like a variation on eco-tourism, because they involve building an actual dome home (probably in a third world country) using AirCrete. Here is an excerpt from DomeGaia’s web page about the workshops:
“This is a hands on workshop, meaning most of the time spent will be outside and actively building. Though there will be some down time when instructors explain the building process and answer questions, you will still be on the building site as these explanations take place, so please come prepared against the elements…. DomeGaia workshops usually include time for yoga, guided meditations, dance, music, and exploring local attractions! Make new friends from around the world, learning, laughing and building together.”
Their website invites you to sign up for a monthly newsletter so you will be notified of upcoming workshops and their locations.
My thanks to the reader who shared AirCrete with me. I welcome your input, too, and let me know if you attend a DomeGaia workshop!