Timmerman Geotechnical Group, Inc., based in Akron, Ohio, was founded as Messmore/Timmerman Services, Inc. in 1976, providing a variety of engineering and material testing services. TGG has continued to grow in size and scope and now offers the services listed below, servicing all of Ohio, as well as parts of Pennsylvania and West Virginia.. Subsurface Explorations. Foundation Analyses. Geotechnical Reports. Construction Quality Control. Laboratory Analyses. Soil,Concrete and Asphalt Testing. Structural Steel Inspection. Building Materials Testing.