Frank Gilbreth began his solo building career when brick and masonry was the preeminent method of building all commercial and large-scale buildings, often with poured concrete foundations and sometimes concrete floor slabs.

When reinforced concrete began to come into more common use for buildings around 1900, as the method was adapted from large-scale construction for dams, canals and the like, Frank moved into the field with gusto but hedged his bets and protected his prized reputation as a bricklayer by forming a secondary company to manage reinforced concrete projects. This also appears to have allowed his superintendents with formal education in civil engineering to operate more independently and use their established credentials to impress clients.