News and Events

Maintenance Maximizes Parking Structure Investment

posted 10.24.2018

When we park our vehicles in a parking deck structure, we don’t typically think about the safety of the structure itself. Fully exposed to the elements in addition to facing the added wear of vehicle loads, parking garages can present unique maintenance challenges. Having a comprehensive maintenance program in place provides owners with routine and preventive measures to verify their parking structure remains functional throughout its service life, creating safe structures, and maximizing the investment.

Identifying Common Issues

The long-term useful service life of a garage relies on the proper specification and construction of the structure, and on the implementation of a periodic maintenance plan. For the construction of new parking structures our teams provide engineering design and review services. We also offer material specification and laboratory services to make sure that proper materials are incorporated at project sites. By implementing a regular maintenance plan you can minimize premature deterioration that can lead to expensive repairs, inconvenience, and safety issues.

For existing parking garages, routine and preventive maintenance begins with a detailed survey of the structure to identify any concerns including cracks, spalls (the results of water damaging the material), sealant joint deterioration, leaks, corrosion of reinforcing steel and structural steel members, and clogged drains. These concerns are recorded and assigned a priority rating for corrective action based on their severity. For example, sealant joint deterioration would typically be assigned a lower priority rating than structural distress and overhead spalling of concrete cover, which could potentially become dislodged and create a life safety risk.

Preventing Structure Failure

Following the structural survey, Terracon can provide an engineered design solution to remediate the deficient conditions so corrections can be made by a skilled contractor. These maintenance services also help to protect facilities users from the risks that come with unsafe conditions which can be present in a poorly maintained structure.

During a recent survey, our parking structures experts identified issues that resulted in a shut-down of the parking deck’s upper level. This parking structure was constructed of pre-cast double tees which used flange-to-flange connections. These connection types provide diaphragm continuity and alignment of the structure, and are designed to resist tensile and shear forces caused by lateral loading. When functioning properly, loading is distributed across multiple connections; however, when a connection fails, the load is re-distributed across adjacent connections. The re-distribution of the loading results in failures continuing to spread along the length of the joint. Improper in-plane shear transfer of the structure can occur and inhibit it from operating as intended.

Terracon’s review of this structure showed an estimated 30 percent of the connections on the upper deck had failed. If not repaired, these connection failures could have resulted in continued failure of adjacent connections and potential catastrophic failure of the deck. Following the survey, Terracon assisted with development of the repair plans and specifications  to remediate the broken connections.

Having completed millions of square feet of parking structure assessments, Terracon’s qualified team can provide periodic visual maintenance inspections that will give a general overview of the condition of an existing parking garage, and establish a plan for proper maintenance of a parking garage.  Terracon can also provide in-depth visual and non-destructive condition assessments of an existing parking garage to evaluate and define the extent of existing deterioration, the causes and problems associated with the deterioration, and develop repair plans and specifications.


Michael Phifer is a department manager in Terracon’s Charlotte, N.C. office. His experience includes building evaluation, design, testing, peer review, building enclosure commissioning and quality assurance for building enclosure systems on projects related to k-12, higher education, healthcare and has served as the project manager for an international investigation project. Michael is a Registered Roof Observer, Registered Exterior Waterproofing Observer and Certified as an infrared thermographer.