Building Monolithic Domes
by Sean Lanham
It's been called a "new paradigm in construction" because it relies on a building process unlike any other. But despite its uniqueness, our monolithic dome construction process has developed a following over the last few years.
One reason for the popularity of these steel-reinforced, concrete buildings is their versatility. Domes can adapt to uses as varied as schools, churches, and sports facilities. Smaller domes can be created for one- and two-story houses. These sturdy, energy-efficient domes are relatively inexpensive to build and maintain. They can cost half as much to heat and cool as traditional structures.
The monolithic dome construction process is fairly simple. It begins with a circular concrete foundation. Next, a canvas-tent-like "airform," fabricated to the desired size and shape, is attached to the perimeter of the slab. Special fans inflate the airform, forming the shape of the dome.
Then a layer of about three inches (eight centimeters) of polyurethane foam insulation is sprayed onto the interior surface of the airform. Steel reinforcing bar, arrayed in a specially engineered horizontal and vertical hoop layout, is attached to hooks embedded in the foam.
Next, shotcrete, a special mix of concrete, is sprayed on the interior surface of the building, covering the rebar. After several inches of shotcrete are in place, a monolithic dome of steel-reinforced concrete has been created.
Because most of the construction work takes place inside the structure, the building process moves quickly. In fact, construction can even proceed around the clock.
The construction of a monolithic dome.
Image: David A. Collins
The St. Agnes Baptist Church in Houston was built with the monolithic dome technology.
Image: Rick Crandall
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