Which roof type is generally found in commercial structures for large open spans?

The roof type that is generally found in commercial structures for large open spans is curved. Curved roofs are designed to provide a large unobstructed interior space, which is a common requirement in commercial buildings such as warehouses, gyms, and auditoriums. This design allows for the effective distribution of structural loads across the roof, while also enhancing aesthetic appeal.

Curved roofs can effectively accommodate various types of insulation and roofing materials, which is critical in commercial applications where temperature regulation and energy efficiency are important. Additionally, the shape of a curved roof can help with water drainage and can reduce the likelihood of water pooling, which is vital for the longevity of the roof structure.

The choices of pitched, flat, and sloped roofs, while functional in various applications, tend to either limit the open space or have different structural considerations that may not be as efficient for the scale and type of spans found in commercial buildings.