Freight at Bush Terminal, New York

Tuesday, February 27, 2024
2pm - 3:30pm ET

Donald Friedman

New York, NY

Registration Fee

Non-Members: $35
APT Members: $20

Emerging Professional Members: $15
Student Members: $10

1.5 LU/HSW/PDH Continuing Education Units

Building structures tend to be categorized using criteria similar to those used for new buildings: as a steel-frame building, as a masonry bearing wall and so on. Structural categories were different in the past because building technology was different, and the categories were generally broader and had more overlaps than those in use today. This case study reviews a building intended to have a concrete frame that is actually a concrete/masonry hybrid.

Learning Objectives: 

  1. Explore the history of reinforced-concrete use in the US.

  2. Compare early concrete designs to modern designs, in terms of code requirements and assumptions.

  3. Identify concrete structural elements based on age, use, and selective probing.

  4. Compare structural models for buildings with solid-masonry exterior walls.

Presenter: Donald Friedman, PE, F.APT, F.ASCE

Old Structures Engineering PC
90 Broad Street #1501
New York, NY

Donald Friedman is president of Old Structures Engineering, and a professional engineer with over 35 years of experience in the investigation, analysis, and restoration of buildings. Mr. Friedman holds a B.S. in Civil Engineering from Rensselaer Polytechnic Institute, and an M.A. in Historical Studies from the New School for Social Research. In addition to Mr. Friedman’s project work, he has taught engineering of historic buildings at Rensselaer, the University of Massachusetts at Amherst, and Columbia University. He is the author of The Structure of Skyscrapers in America, 1871-1900, After 9-11: An Engineer’s Work at the World Trade Center, Historical Building Construction, and The Investigation of Buildings. Mr. Friedman is also the 2023 APT Preservation Engineering Technical Committee (PETC) recipient of the David Fischetti award for his engineering article titled, “Understanding accidental hybrid structure: an early concrete warehouse in the USA,” which is the basis of this presentation (Proceedings of the Institution of Civil Engineers – Engineering History and Heritage 176(1): 18-24 (2023), available for download: