Nicholas Lehmann is an expert in the field of structural investigation of existing infrastructure. He has investigated, analyzed, and designed repairs for hundreds of steel, concrete, timber, and masonry structures and associated systems, such as waterproofing, sealants, and expansion joints. He specializes in structural damage and collapse investigations, condition assessments, disaster response, construction document preparation and specification writing, and nondestructive testing. After the events of September 11, 2001, Nicholas investigated the World Trade Center site and surrounding buildings for debris impact damage, as well as performed on-site engineering related to the recovery efforts at Ground Zero on behalf of the New York Office of Emergency Management.

Nicholas has extensive experience in the investigation and repair of concrete structures. He has utilized various non-destructive methods to evaluate both modern and historic concrete structures and materials in a variety of locations and environments, including tunnels, water vessels, historic buildings, parking garages, and industrial facilities. He currently serves as President of the International Concrete Repair Institute, Delaware Valley Chapter, and has taught courses on concrete deterioration and repair at the University of Pennsylvania and elsewhere.