That depends. Don’t you love it?

The truth is, there are many factors that influence the prediction of how long a parking structure will last and at what point you will need to tear it down and rebuild.

Parking structures are unique in that the structure is directly exposed to the elements, unlike a building structure that is protected by a Building Envelope. Exposure includes moisture, freezing temperatures, deicing salts, thermal expansion and contraction, and dynamic vehicle loads. All these elements work to degrade the structure and start doing so even before the structure is open to patrons. After that, degradation accelerates over time. Figure 1 shows the degradation of a parking structure compared to a building structure over time. As can be seen, the only way to extend the life of a parking structure  is with maintenance, the cost of which can be minimized with proper timing.

To further complicate things, different structure types may have lower initial construction costs but higher maintenance costs, as can be seen in Figure 2.

So back to the original question, which we are often asked after degradation is found that needs repair.

To predict the remaining life expectancy, several things can be done to base the answer on. First, testing can be conducted to determine the state of protection of the concrete reinforcement from corrosion.

The testing includes Chloride Ion and Carbonation Penetration Testing as shown in Figure 3. If the penetration of either has not reached the reinforcing steel, there is some useful life left which can be further extended with a traffic coating membrane. If the penetration has reached the reinforcing steel in limited areas, partial slab replacement is an option. If more widespread, total slab replacement or replacement of the entire parking structure may need to be considered.

Assuming (based on this testing) that there is adequate remaining useful life of the structure, a maintenance program can be developed, which if followed,  can help with estimating a life expectancy along with a budget and plan to get there.

The IEI Structural Engineering Advantage

The engineers at IEI specialize in parking structure restoration. They will be glad to walk your facility and let you know of any conditions that require immediate attention, what maintenance activities you can perform and when, to extend the life of your facility at minimal cost. IEI can also conduct the necessary testing to determine the useful life of your parking structure and help you prepare a maintenance schedule. Give them a call today.

• Trusted Resource: IEI’s expertise is trusted by owners and property managers of all sizes, including some of the nation’s largest property portfolios. In addition to answering the request for advice, consulting, and peer reviews, IEI is sought after for their expertise in the form of educational speaking events for national organizations as well as articles in major national publications.
• The Right Level of Expertise: The IEI professionals performing your work are graduate and professional registered engineers. They possess the necessary engineering fundamentals required to understand the many elements that affect the performance of your faculty.
• Sounding: For evaluating solid surfaces, IEI utilizes a state-of-the-art sounding tool that can not only be used on horizontal but vertical and overhead surface as well. Sounding identifies voids, delamination, and future spalls.
• Industrial Rope Access: The IEI engineers have extensive training in SPRAT Certified Industrial Rope Access. Not only are dedicated tested and certified roof anchors not required for this method, but it allows for efficient access to 100% of a building’s facade compared to a Rope Descent System (RDS) or Swing Stage which accommodate very limited access.
• Thoroughness: IEI is commonly complimented, by its existing customers, for being thorough. IEI’s state-of-the-art techniques provide a more thorough Condition Assessment. The time to know the true extent of any deficiencies is now, not after the restoration contractor has started work which leads to change orders and damaged reputations.
• Real Time Cost Estimates: IEI’s relationship with some of the nation’s top restoration contractors allows for accurate real time costs estimates. The time for accurate cost estimates is now, not after the work is budgeted and the bids come in that are too high. IEI estimates are typically within 5 to 10% of actual qualified bids.

About the author

Scott Weiland

Principal Structural Engineer with Innovative Engineering Inc. has over 37 years experience helping owners reduce parking structure maintenance costs. He can be reached at 770-517-5507