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Tick tock, tick tock. Time is starting to catch up with the Seventh Street and Grand Avenue parking garage, which was built in 1974, as it enters into the twilight of its career in need of structural repairs to remain open.

“It is kind of like people; every year you get a little bit older and at some point you retire,” said Gary Fox, Des Moines’ city traffic engineer, who is responsible for the city’s parking system.

Retirement is getting closer and closer for the 35-year-old parking ramp. With age often come trips to the hospital for operations, and this garage is ready for its first major one – at an estimated cost near $500,000.

Not bad, considering health-care costs these days.

The Des Moines City Council on Oct. 12 approved the rehabilitation of the ramp, which should help it reach its full 45-year effective life. If all goes well, the structural repairs will enable the garage to remain open at least until 2019 – though according to Fox that is just an approximation.

“The thing doesn’t go from being in excellent shape one year to being ready to be torn down the next,” he said.

What was wrong?

There are a wide range of repairs to be done on the garage, but the most serious repairs, said project manager Jon Fussell, have to do with deterioration problems with some of the precast ledger beams. According to the winning bid from RAM Construction Services of Minnesota, the rehab will involve 2,700 square feet of beam repairs costing $143,100, the largest expense in the project.

Also of structural importance is the deterioration of tee connections. Workers will carry out 1,000 square feet of repairs on tee connections at a cost of $68,000.

The ledger beams and the tee connections help hold up the floor that cars travel on.

Newer garages are built with special concretes and epoxy-coated steel that is less susceptible to deterioration; older garages tend to be more affected by the weather. Fussell said older concrete, like that in the Seventh and Grand garage, is more porous and allows melting saltwater during the winter to reach the steel reinforcement members in the concrete, which can cause the steel to begin to corrode.

RAM Construction had the low project bid of $463,000, which was 8 percent below the city engineer’s estimate of $503,315. The company previously worked with the city to do repairs on the city’s oldest parking garage at Fifth Avenue and Walnut Street, Fussell said.

There were also minor repairs included in the total project cost at both the Third Street and Court Avenue and Fourth Street and Grand Avenue parking garages, which need work mostly in the stairwells, according to Fussell.

Fussell said the plan is to go in and repair the ledger beams and tee connections through the use of carbon fiber, and in some cases with conventional concrete and reinforcing bars. The carbon fiber reinforcing polymer will be wrapped around the concrete to form a sort of carbon fiber envelope to hold everything together. That should ensure the structural integrity of those points.

How bad was it?

The Seventh and Grand garage was unlikely to suffer a catastrophic collapse anytime soon, Fox said, but if the repairs had been pushed off there would have been an increased risk of a problematic failure.

“Falling concrete would be more likely, but it is possible that a beam could come down, and there is always that risk,” Fox said. “Most of the vehicles in the garage are unoccupied, but certainly there are times when people are driving in and out, and if the wrong beam fell at the wrong time, then there could be a vehicle under it and it could cause injuries or worse.”

Fussell said the problems with that garage were caught “long before” they would have created a danger to anyone, but said that since the garage was built, there hasn’t been any appreciable money put into the structural system.

“It’s like everything else; it’s like your own home. If you don’t maintain it, you are going to have problems,” he said. “The longer you put them off, the worse they get.”

In late June, the middle section of a 7-year-old parking garage in Atlanta collapsed from the fourth floor down, crushing approximately 45 cars but causing no injuries or deaths. The cause of that collapse has still not been determined.

Fox said a full collapse in the Seventh and Grand garage from a failed beam is unlikely but possible.

“There are different ways that beams can fail; now you are starting to talk about things we get kind of nervous about,” Fox said. “Typically most structures are designed so that if a beam fails, it doesn’t really fail in a catastrophic manner. But it is possible that a beam could fail bad enough that it would fall down, but it seems very unlikely that it would actually then trigger a whole domino effect that would take down other beams and all that kind of stuff.”

Normally, Fox said, if something as catastrophic as a beam collapse were about to happen, the concrete would crack, giving advance notice of the problem.

The city inspects its eight garages every two years, and hired Walker Parking Consultants two years ago to do a full inspection. The latest inspection came earlier this year. Fox said the structural analysis didn’t find any risk of collapse.

The repairs to the Seventh and Grand facility will more than anything extend the life of the garage.

“We don’t just go in there and do every little thing,” Fussell said. “We like to get them to a point where we feel we haven’t got an immediate problem, and we can repair them fairly easily.”

What’s next?

Even with the planned repairs, the Seventh and Grand garage is only about 10 years from the end of its effective life, and the Fifth and Walnut garage is just five years away. Reaching the effective life date means that officials will have to consider a plan of action. Fox said it isn’t a given that the garages will be torn down and rebuilt.

“That is something we have indicated we are going to take a long look at as these garages get older and need to be replaced or need to be taken out of service, whether or not they actually do get replaced,” he said.

Parking garages aren’t cheap. A $500,000 repair is a drop in the bucket in comparison to the $16 million Fox estimated it would cost to construct a 1,000-space garage. Fox compared Des Moines and Chicago and said parking rates here are around $100-$110 per month in comparison to garages in Chicago that charge $300-$400.

“We really struggle along trying to keep our rates as low as we can in order to have enough money to operate the system in a good manner and provide a good level of service for our customers and then have money to pay for the garages and the money to pay for these necessary repairs and major maintenance in order to get the full service life out of it,” Fox said.

Repairs on the garages will begin soon, but some of the work is temperature sensitive and will have to wait until spring.

The city has no plans for repairs on the other garages – their retirement is far away.

But for the Fifth and Walnut and the Seventh and Grand garages, the clock is ticking.