STEEP HYPERBOLIC PARABOLID
This type of warped surface shell utilizes steeply pitched surfaces. Each panel is arranged so that one corner is out of the plane of the other three corners. Ribs are formed between adjacent units and additional ribs are required at the outer edges of the structure. A church using hyperbolic paraboloids was built by Felix Candela in Mexico City, and some of the surfaces are nearly vertical. No top forms were used for the concrete. A network of reinforcing held the concrete to the form. In cases where four panels came in at a low point, columns were used to support the structure.