Accidents happen. Sometimes for the good. For instance, the discovery of pennicilin was due to an accident in a laboratory. Newton’s discovery of gravitation resulted from a blow to the head while sitting under a tree. Buddha attained enlightenment while sitting under a tree. That wasn’t an accident so much, but he was sitting. And one day, while I was sitting at my desk, a tiny accident changed my life. I was working for one of the great industries of my state when someone delivered a copy of Compressed Air Technology magazine to my desk. It was addressed to Mr. Antonio Meraginaro or something like that… it was a long time ago. But I do remember that, on the cover of this industry magazine, was a picture of a huge, smooth concrete dome. The Monolithic Dome. I wasn’t sure how compressed air was involved with monolithic domes, but I happened to have an interest in the subject since I’d almost sent for information on monolithics once before, after seeing the ad in the back of either Popular Science or Popular Mechanix magazine. Maybe both. It said “monolithic domes.” It featured a picture of the following house on a beach in South Carolina.
How much more super cool could you get than a house like that? So I read the article in the accidentally delivered magazine and discovered that monolithic domes are made entirely out of air.
Well, not exactly. They’re built using compressed air to inflate a large tent-style balloon called an airform, which defines the shape of the final building. The domes you see above are made that way, the airform being a permanent part of the structure. The monolithic dome comprises four construction elements: the airform, expanded foam, reinforcing bar, and concrete. The Compressed Air Technology article was interesting and well-written. I think it included the graphic below, from the Monolithic Dome Institute.
The process is not complicated. One lays a ring beam of reinforced concrete, then attaches the airform around the beam and inflates it. An airlock allows workers to enter and leave the fully inflated airform without disturbing the air pressure. This air pressure is critical to maintaining the proper shape for the dome.
One applies a few inches of polyurethane foam to the inside of the airform. The foam expands and becomes rigid, like a foam cooler box in the shape of a dome. Next, one places rebar hangers in the foam layer, then sprays more foam to embed them. Next one ties rebar to the rebar hangers, lining the interior curve with steel, according to a precise engineering plan. One sprays shotcrete until the rebar is completely covered and the interior of the dome looks like a hollow concrete egg. The air pressure must be maintained until the concrete has sufficiently cured.
When the inflator and airlock are removed, the airform is left in place to protect the foam layer from sun and moisture. The airform, itself is susceptible to those exposures, so it must be covered with stucco, paint, tile, stone or any of several other surface treatments to protect its plasticized fabric over time. Many different approaches can be seen at the Monolithic Dome Institute in Italy, Texas, including metal cladding and vine-covered sections of chain-link fence. These domes can also be buried under a few inches or several feet of earth.
Once the concrete has cured and the exterior has been treated to protect the airform, a monolithic dome can be expected to last for hundreds of years with very little maintenance. Moreover, this structure easily survives hurricanes, tornadoes, wildfires, bullets and bunker-penetrating missiles. That’s not a joke. When the US was still on good terms with Saddam Hussein, the monolithic people built 28 monolithic domes in Iraq, 27 being for grain storage and one for a mosque—the building shown below. A missile punched through this dome with a 5,000 pound warhead. It exploded inside the dome but left the dome structurally sound. It needs massive repair but it won’t be falling down.
Monolithic published an email from a US helicopter pilot who used a reinforced concrete dome for missile targeting practice. He said “…we had teams shooting rockets at it for months before someone finally was able to punch a hole in it. Even direct hits would often glance off of it, it was pretty impressive.”
Here, they strength-test a dome at BYU Laboratories. They couldn’t pile enough weight on it to break it. They had to demolish it with jack hammers.
Pensacola’s incredibly beautiful Dome of a Home survived both Huricane Ivan in 2004 and Hurricane Katrina in 2005 with minimal damage while structures all around were completely destroyed.
So…to have a house that looks like this and is almost indestructible…how could that get better?
Well, super-insulated with polyurethane foam, the monolithic dome can pay for itself in energy savings alone.
As a fact of geometry, a dome shape encloses twice the interior volume of a “square” structure with the same surface area. A dome uses half the surface area to enclose the same volume of space so it has half the rate of heat exchange with the external environment. But with several inches of rigid foam between the interior and exterior, the energy exchange is even lower. It takes very little energy to heat or cool a monolithic dome. And it takes relatively little building expense to produce an interior like this:
The truth is, the monolithic dome folks are outright geniuses. And the head genius of them all, the industrious inventor of the monolithic dome, is a most unassuming man named David South.
A fan of Buckminster Fuller since hearing him speak on the radio in 1956, David South actually met and spoke with Fuller and went on to build numerous Fuller-style domes with pentagon/hexagon construction. He encountered what he says is a persistent problems with geodesic domes: with all the angles and joints, they’re very hard to waterproof. Working with polyurethane foam, he got the idea to spray it on the inside of an inflated airform to produce a hollow egg shape. The foam was even rigid enough to maintain its shape but not to bear much of a load. Lined with reinforced concrete, it became the monolithic dome. South patented his concept in 1979 and has since built massive domes for churches, potato and grain storage, oil and fertilizer storage, homes, water storage, churches and community centers. He’s built in many countries and for all kinds of people. He runs dome-builder training courses twice annually at his Italy, Texas, Monolithic Dome Institute, where attendees learn about concrete and steel and also participate in building an actual dome.
I attended this workshop in 2009 and gained experience spraying polyurethane foam, setting rebar hangers and spraying shotcrete in the cavernous, eerily lit space of a dome under construction. The door and window spaces are defined by the rebar placement and concrete is not sprayed there. These spaces are opened after the concrete cures. It’s a fast and fascinating way to build a structure that can last hundreds of years.
Wallace Neff’s Bubble Houses
Oddly enough, an architect named Wallace Neff built very similar domes in the 1930s, producing what he called the Bubble House, intended as fast, easy, inexpensive and durable housing for common people, intended to eliminate the persistent burdens of housing economics for the masses. Neff, too, built with inflated airforms and reinforced gunite, but he applied the concrete to the outside of he airform and included no insulation. South had already built several foam insulated domes with his monolithic process by the time he learned about Neff, but their general approach is very similar. Neff worked internationally to build Bubble House communities in impoverished nations, including 2,500 domes in Cuba. Neff’s design is most similar to South’s Ecoshell I design, which includes no insulation.
Domes for the World
Again, independently but very similarly, the Monolithic Dome Institute has envisioned housing the world’s poor in small domes through their Domes for the World Foundation, training locals to build the domes and creating villages of adequate housing to replace homes destroyed in natural disasters.
So much disaster recovery is worth less than a bandaid but costs as if we were building palaces. Monolithic ecoshell housing is cheap, safe, green and virtually permanent. And it teaches the local people valuable construction skills. With small domes like these, the concrete can either be sprayed on or applied by hand in a day. The Monolithic Dome Institute is a truly unique and humanitarian organization with a sustainable vision for the future.
Single Resident Occupancy
While David South’s domes are seriously different from Buckminster Fuller’s, South shares one thing with Fuller exactly. David South seeks solutions that will benefit every person who lives on the earth while making as little impact on the environment as possible. An extremely practical man, focused on real needs and effective function, he also pays close attention to people’s expenses. One point he makes very strongly is that there is a serious shortage of Single Resident Occupancy housing in the United States. The studo or efficiency apartment is one approach to meeting this need, but most apartments are made for a family, with room for four or more people. Older individuals or couples don’t really need two bedrooms and all the expense that goes with them.
One solution South devised is the very small dome of 16.5′ or 20′ diameter built in small groups and operated as weekly-residence inns with all utilities included. A complex of such domes with 4 to 50 or more units, can provide comfortable, safe, quiet space with extremely low utility costs. Operated on a weekly residence basis, there are no leases, though the rules may change after a resident remains a certain length of time. South promotes these complexes as uniquely profitable nvestments as well. With low cost of construction and maintenance, the weekly rental rates and low utility expense allow the builder to repay the initial investment in relatively short order, after which, it’s purely income-producing while also serving a vital public need. He says that his complexes stay fully rented, with a waiting list to get in.
I’m glad, then, that someone accidentally delivered a copy of a magazine to me many years ago and put me on the road to learning about monolithic domes and their remarkable inventor. Having attended their dome-building course and kept up with the organization through their website, I’ve been educated, entertained, amused and astounded by the outporing of inventive attention to some of the most important issues of the modern world. The monolithic design and the way this organization has promoted and developed it are an important resource as we move into an age of changing climate and apparently increasing natural disasters. Wildfires seem to get bigger and stronger every year, as do tornadoes and hurricanes. I’ve incorporated a small monolithic dome into my Energy Garden concept for a children’s educational field trip destination and I want so badly to live in a monolithic dome I can taste it. I’m determined to make a monolithic dome my next permanent home.