Lon S. Erlandson, P.E. Senior Forensic Engineer

Lon S. Erlandson, P.E.

Senior Forensic Engineer


About Lon

Lon S. Erlandson, P.E., Senior Engineer, for Lerch Bates Forensics. Lon has extensive experience in construction projects from both the design and owner’s perspective and in the forensic analysis and testing of failed structural and envelope systems. He has performed non-destructive tests on building materials, geotechnical evaluations and testing, and exterior cladding evaluations including historical masonry building rehabilitation projects. Lon has also acted as a construction manager for multi-million-dollar health care, educational, and senior living projects in the upper Midwest.

His responsibilities include forensic evaluations of residential and commercial facilities, building performance testing including air leakage and water penetration, steep slope and low-slope commercial roof analysis, building code reviews, and technical report production for the insurance and legal communities and expert witness services. Lon has assisted in historical building evaluations and coordinated one of Lerch Bates’ largest engineering claim evaluations that included over 120 buildings affected by a weather event.

Area of Expertise

  • Investigations and Field Review of Existing
  • Construction Defect Litigation Support Thermal Analysis
  • Building Code Reviews
  • Construction Management
  • Low- and Steep-Slope Roofing Systems
  • Agricultural Facilities and Production
  • Air Infiltration and Water Penetration Testing
  • Non-Destructive Evaluation
  • Damage Assessments, Engineering Analysis, Repair Scope Preparation

Related Experience

  •  City of Sioux Falls; 100+ Building Storm Damage Assessment; Sioux Falls, SD (Forensic)
  • Various Personal Injury Cases; Site Condition Assessments and Building/Existing Building Code Reviews; Various Dates 2017 to Present; Minnesota
  • Boys Town; 121 Building Storm Damage Assessment; Omaha, NE (Forensic)


  • Bachelor of Arts in Economics, November 1990, Moorhead State University, Moorhead, Minnesota
  • North Dakota State University, B.S. Civil Engineering, 1998

Registrations & Certifications

  • Licensed Professional Engineer in MN, ND, SD, WI, IA, and NE

Office Location

Minneapolis, MN

Contact Lon

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