Mayes Testing Engineers, Inc.

We are one of the leading providers of construction quality assurance services in the Pacific Northwest. 

Our services include construction materials testing and special inspection. With one of the largest staffs of WABO registered inspectors in Washington, backed by Terracon’s national network, our team is ready to assist today.


We provide structural inspection and material testing required by local building codes. Services include:


  • Asphalt & Soils Density
  • Reinforced Concrete
  • Post Tension Concrete
  • Shotcrete & Grout
  • Fiber-Reinforced Polymer
  • Fireproofing
  • Intumescent Paint & Firestopping
  • Lateral Framing & Wood Timber
  • Masonry
  • Post-Installed Anchors
  • Shoring Materials
  • Structural Steel/Welding

Nondestructive Testing

  • Ultrasonic Testing
  • Magnetic Particle       
  • Dye Penetrant
  • NDE Level III Consultation

Materials Laboratory Testing

  • Concrete
  • Masonry
  • Physical (Steel)
  • Soils
  • Asphalt
  • Aggregate


Mayes Testing Engineers, Inc. is approved by the Washington Association of Building Officials (WABO). Our laboratories are A2LA Accredited and WSDOT validated.

All testing is performed in accordance with:
  • American Association of State Highways and Transportation Officials (AASHTO)
  • American Concrete Institute (ACI)
  • American Society for Testing and Materials (ASTM)
  • American Society of Nondestructive Testing (ASNT)
  • American Welding Society (AWS)
  • International Code Council (ICC)


Come join our team

Featured Post


Local news about our Seattle and Tacoma Materials Teams

What is an “apogee”? It is defined as a highest point or culmination. Terracon’s group of inspectors, technicians, administrators and engineers hit apogees on a daily basis. Here is where you can experience the highs for yourself.

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