Concrete is more expensive than steel, but tends to remain steady in price, giving builders a good idea of how much money they should expect to spend in material costs for the project. Although concrete costs more upfront, especially cast-in-place concrete, builders save up to 25 percent in property insurance, according to Alfred Gerosa of the Concrete Alliance in New York City. Steel is cheaper overall, but insurance costs are higher because insurance companies know that steel is less stable, especially against fire.
Availability of Materials
Cement, used to make concrete, can experience a shortage in availability of the material. The shortage of concrete's availability due to shipping rates and imported materials can drive up costs and limit supplies, despite growing demand. Steel is readily available, according to John Cross, vice president of marketing for the American Institute of Steel Construction.
Concrete is notably safer and sturdier than steel. It is able to resist fire for extended lengths of time. Concrete structures are less likely to collapse in the event of a fire, since they are able to handle higher temperatures for longer lengths of time. Steel will both soften and melt when exposed to high temperatures for longer time periods. Builders can improve safety by using spray-on fireproofing spray, which strengthens the steel. Steel is ideal for seismic zones, reports Larry Williams from the Steel Framing Alliance, since it can bend and absorb energy from earthquakes.
Steel buildings are designed with more flexibility than concrete structures, since contractors can choose from different weights and strengths of steel. Concrete, although limited in design, is able to withstand more weight. Many times buildings are built with both concrete and steel, depending on the design needs, for the best possibilities.