Dome schooling: across America, concrete domes are being used as school buildings

Concrete Construction, Feb, 2003 by Sean Lanham

Rebar Hangers Steel reinforcing bars are attached to the foam using a specially engineered layout of hoops (horizontal) and vertical steel bars. Small domes require small-diameter bars with wide spacing. Large domes require larger bars with closer spacing. The first rebar hanger is attached at the top center of the dome. To secure the center top hanger, a thin layer of foam is sprayed over the hanger. If rebar hangers are not covered with enough foam, they will not be secure enough to hold the rebar. Sometimes two hangers are placed at the top in the unlikely event that one breaks.

Concrete Application The final step in building a monolithic dome is the application of shotcrete to the interior surface of the structure. Just as with the rebar, the exact amount of shotcrete is determined by engineering specifications. But typically, the shotcrete in a dome home is about 3 to 4 inches thick. Once the shotcrete has been applied, the blower fans are shut off and the monolithic dome is complete, while the shotcrete in a school is about 5 to 6 inches thick.

--Sean Lanham is a Dallas-based writer who frequently reports on the monolithic dome industry. Freda Parker contributed to this article.