Headquartered in Willowbrook, Illinois, Raths, Raths and Johnson is a structural engineering consulting firm specializing in the investigation, analysis, repair design, and rehabilitation of existing buildings and structures. Founded in 1968, the firm provides forensic structural engineering, building envelope consulting, structural restoration design, and expert witness services for complex construction litigation and insurance cases. With 100+ licensed structural engineers, RRJ has investigated and designed repairs for hundreds of commercial, industrial, and institutional structures across the United States. Their expertise in concrete deterioration, masonry restoration, parking structure rehabilitation, and waterproofing systems makes them a preferred consultant for property owners and developers nationwide.