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About Us

Pioneering Solutions For Our Clients And The World We Live In Today

Twining’s legacy dates back more than 125 years. What started as a family business in 1898 has evolved into one of California’s largest service providers of multi-disciplinary engineering services. Highly regarded by owners, developers, contractors, consultants, and the industry for providing high-quality services that are reliable, timely, and compliant, Twining has been a central part of some of California’s most regionally significant construction projects. We employ some of the industry’s most well-known construction experts who perform research as well as consult with regulatory agencies to shape the future of construction standard practices.

Twining is a full-service engineering company with unmatched technical expertise. As detailed below, our services span from QA/QC, materials testing, and inspection to highly technical capabilities in applied engineering and integrated disciplines. With laboratories throughout California and a deep bench of engineers, technical experts, materials scientists, technicians, and inspectors, we are unequaled in our core competencies to serve the built environment:

  • Geotechnical Engineering
  • Asphalt Pavement Quality Assurance Services
  • Asphalt Pavement Design and Materials Evaluations
  • Soils and Materials Testing and Inspection
  • Specialty Testing
  • Mobile Laboratory Services
  • Roofing and Waterproofing Consultation and Inspection
  • Applied Engineering and Research
  • Forensic Evaluation
  • Concrete Engineering and Materials Science
  • Stormwater Management
  • Geo-Instrumentation Monitoring and Assessment
  • Third-Party Product Testing
  • Plan Approvals and Inspection
  • Petrography
a piece of glass being made in a factory

Our Mission

In cooperation with our clients, we protect the public and our communities by providing engineering, testing, and inspection services to help ensure quality and conformance with construction standards within the built environment.

By empowering and encouraging our team to act with integrity and to be responsive, we contribute to the success of the projects we service.

Our Values

The industry leader in technical innovations and quality service, providing advanced geotechnical engineering, special inspection, and materials testing solutions.

  • We always operate with integrity and character.

  • We sustain an environment that enables great people to do extraordinary things.

  • Our employees are the most valuable asset both to us and our clients.

  • We promote innovative thinking as a way of life.

  • We cultivate and value lasting relationships with our clients and our stakeholders.

Pioneering New Standards

Twining possesses full-service construction material testing laboratories that are certified and/or accredited by all major governing agencies.