Commercial Building Foundation Repair

Parking Garage Collapse

“Parking Structures have the lowest factor of safety built into their design. Couple that with poor inspection and maintenance practices, and you have a recipe for a very expensive problem”


Parking Garage Collapse


If you google parking structure collapse or damage, you will find there are quite a few instances around the United States on a yearly basis. Some are quite sensational, others caught in the nick of time before someone was injured or killed.  If you consider the actual number of structure failures versus the number of parking structures, the number is miniscule, but the key element in every single story you read about is lack of inspection and maintenance coupled with the fact that parking structures have the lowest factor of safety built into the design.  That statement alone should awaken every single property management company throughout the west. Poor inspection and maintenance practices coupled with a lower design safety factor, should open your eyes to the need for better management practices.


“Another flaw in the human character is that everybody wants to build, and nobody wants to do maintenance.”  - Kurt Vonnegut


A little back story on structural design for parking structures.


Structural design is generally done by computing an anticipated load (how much will the stuff in the building will weigh), multiplied by a safety factor, and then designing a structure with enough strength to support that “factored” load.  Modern building codes estimate the anticipated strength as less than it actually is, (for errors in materials/construction). Structures generally end up with at least 3 times as much strength as they need. So, the building you are sitting in is quite safe.  Unfortunately, parking structures typically have the lowest factor of safety built into their design, thusly they fail much more often than other building types because they’re so cheaply constructed or the loading is so much lighter than other types of structures that factoring doesn’t increase the loading by as many tons, and finally failures rarely result in loss of life.  


Parking structures, especially pre-stressed concrete structures are designed so that if they fail, the rebar, (steel), is the last thing to go, which will stretch gradually when failure begins so that people have a chance to “get the heck out”.  The alternative failure is what’s called a brittle failure, where there’s just one loud pop and then bam, collapse occurs with no warning at all.


 Engineers always talk about this stuff in terms of ‘strain’ and ‘yield.’ Strain is how much a material can deform (stretch or compress). When the strain gets too much, the structure ‘yields’ or permanently deforms. For a concrete structure, deform means eventual collapse. The last thing to go before a concrete structure collapse is the reinforcing steel, which has a maximum strain of about 0.02 (2%) before yielding. That means if the clear span (beam-to-beam distance) is 30 feet, you can have a sag of 30 ft / 2 * 0.02 - 3.6 inches before it actually damages the structure. Parking garage widths are typically 64 feet, which can have 7.5 inches of sag in the middle, far more than the allowable sag for potential damage. Combine this with environmental conditions that allow water and salts to reach the embedded steel, and you have a recipe for a potential collapse, or at the very least, a very expensive repair project.


So, now you know a little about all those parking structures you manage.  Would you be interested to find out the condition of them as well?  Foundation Tech, Inc. offers detailed inspection reports and structural assessments along with ACI certified structural concrete repair services throughout the western states.




Retail Store Foundation Repair

Is your parking garage safe?

Is your parking garage safe?Professional engineers across the U.S.  say safety oversight of parking structures is a rare occurrence nationwide. Yet parking garages are significant and costly pieces of civil infrastructure that are subjected to intense stresses that other structures are not, such as corrosion from salts, automobile exhaust, weather, and the on-again, off-again weight of parked cars. In California, seismic inspections only occur when major earthquakes happen, but every shake can cause damage.


When they fail, the results can be devastating. A parking deck collapse in Atlanta in 2009 damaged hundreds of vehicles and led to hundreds of thousands of dollars in insurance claims. A concrete slab fell from a garage in Milwaukee in 2010, killing a 15-year-old boy and leading to a $39 million judgment against a contractor. Even the small pieces of spalling concrete that fall from a ceiling can cost thousands in damage claims.


Days before the Atlanta collapse, another east coast city closed the top two floors of their parking ramp following a structural assessment identifying the need for more than $700,000 in repairs – to extend its life to only 2018. The incoming Mayor has advocated for demolition of the ramp since he took office, saying “years of neglect and inaction” had left it in dangerous shape.


Across California and the U.S., parking garages everywhere are in bad shape. In 2006, a 3.5-ton concrete panel fell from a public parking garage onto a truck. No one was hurt in that incident. Incidents like this are happening everywhere as our infrastructure ages.


The recent collapse of a condo with underground parking in Florida should have opened everybody’s eyes.  Killing over 100 people and multiple inspections without a single repair has send shudders into every building and safety department across the U.S. There isn’t a building department that wants to be the next city on the list of neglected inspections and required repairs.


Despite these and other cases of collapse, no state or national agency except New York currently tracks inspections or maintenance of parking structures. The California state Department of Transportation inspects bridges on a two-year cycle, but parking structures are not in its portfolio. The federal Occupational Safety and Health Administration covers 7 million workplaces but inspects only those where priority complaints are registered. A review of its online inspection database going back to 1990 found no reports of a parking structure inspection anywhere in its jurisdiction.  The city of Santa Monica has recently began inspecting all its parking structures, and the finding were astonishing. Over 80% of city owned, and private parking structures, require repairs. But engineering professionals agree regulatory agencies largely ignores parking ramps and their operators.


The responsibility to determine how often a structural assessment is conducted is left to the property owner. It is up to a parking deck’s owner to determine how often a structural assessment is conducted. Some national property management companies have set repair programs, but this isn’t common. Is your parking garage safe?


One thing that the Miami collapse has taught us is, the potential for loss and the lack of regulatory oversight is frightening.   But, the absence of regulation does not mean owners operate in the dark. Industry groups such as the American Concrete Institute and professional organizations such as ASCE have identified best practices for inspecting parking ramps, and the National Parking Association trade group recommends a two-or-three-year inspection cycle. Operators have no mandatory code to follow, but they have plenty of guidance available. It is the owner’s responsibility to take care of its assets, and there is a lot of information out there to help owners do that.


Properly maintained and serviced when needed, a concrete parking structure can have a service life of 40 years or more, according to engineers and to maintenance guides available online from the National Parking Association trade group. Sound policy calls for maintenance to be done whenever a problem is spotted.


The why’s and what to look for’s

In areas of freezing weather, De-icing agents often contain chlorides that can cause deterioration of the structural steel beneath the concrete. Along the coast, the corrosion effects of salt moisture in the air is even more prevalent. When steel expands from stress, it often causes portions of the concrete to pop off or “spall.”  Spalling is a sign of corrosion beneath the concrete. Automobile exhaust has a major detrimental effect on both concrete and the embedded steel. Delamination often occurs where no other cause has been determined, leading engineers to study the effects of corrosive gases on parking structures.


Owners and property managers are going to want to make sure there is no corrosion that will compromise the ability of a parking structure to operate. The longer a problem is ignored, the more expensive it is to repair.


It is well known in the structural engineering community that parking structures are subject to an aggressive corrosive environment. Corrosion of the embedded steel reinforcing bars is a major issue and should be inspected on a regular basis.


Structures, including parking ramps, are built in such a way that they give signs of distress.  If steel becomes so corroded that the structure threatens to fail, it will give signs to those who know how to read them. When you see beams deflect or crack, that is a clear indication the structure is in trouble. The structure will show off signs of distress before the actual failure. Maintenance is generally good for any house, building, tower, or bridge.  All structures deteriorate to some extent, and owners must manage it so the structure does not deteriorate to the point where it will affect its operational condition.



  • Statewide codes do not mandate inspections for public or private parking structures. No state agency is monitoring their condition.
  • Unlike other buildings, parking garages are subject to the corrosive effects of salt and the constant pounding of vehicles.
  • No agency is charged with ensuring that public or private owners comply with structural engineers’ recommendations for maintaining parking structures.
  • When an inspection is performed on a private parking structure, it is not accessible to the public.
  • Regular inspection schedules will ensure maintenance and repairs that can keep your parking structure open and in good health.


Foundation Tech, Inc.  

Foundation tech, Inc is a specialty contractor located in northern Los Angeles.  All services are self-performed by trained repair technicians, including ACI certifications for specific repair procedures. Our services include.

Structural Condition Assessment Reports

Non-Destructive Corrosion Potential Mapping

Cathodic Corrosion Protection

Carbon Fiber Structural Bracing - CFRP

Penetrating Waterproofing Products

Positive-Negative below grade waterproofing

Crack Injection

Post Tension Repairs/Upgrades

Concrete Spall Repair

Micro-piles/ Piers/Helical piles for load support

Seismic Bracing


Our advanced condition evaluation techniques and expert knowledge allow us to provide clients with a preliminary understanding of structural conditions at a reasonable cost. A condition evaluation or condition survey begins with a visual walk-through, followed by either a preliminary or detailed survey to identify the extent of distress, potential causes, and potential deterioration mechanisms. The condition survey is generally a precursor to extensive investigation, testing, and repair recommendations. In every case, Foundation Tech, Inc. uses its vast experience from prior projects to perform the best possible condition assessment within the client’s budget.

Clients usually ask to:

  • Obtain general assessment report about distress and/or damage
  • Get a routine inspection to maintain a structure
  • Provide detailed cost estimates for a full-scale investigation and repair recommendation
  • Provide specific repairs based on repair recommendations by others.


We can be reached at of for immediate assistance with your parking structure or building, contact;