Structural engineering — a specialty within the field of civil engineering — focuses on the framework of structures, and on designing those structures to withstand the stresses and pressures of their environment and remain safe, stable and secure throughout their use. In other words, structural engineers make sure that buildings don’t fall down and bridges don’t collapse. Structural engineers design roof framing (beams, rafters, joists, trusses), floor framing (floor decks, joists, beams, trusses, girders), arches, columns, braces, frames, foundations and walls.