Detecting Decay in the Garage

For co-op and condo boards, a parking garage can be a prized amenity, a convenience for residents and a great source of income. But neglect can turn those amenities into liabilities. In your engineering work, do your clients tend to ignore problems in their parking garages before they call you?

Yeah, generally they do ignore it, I think because sometimes they don’t realize the simple things to look for that create problems. So they do ignore the potential for problems. Absolutely.

Do you tell them that they should have experts on hand to inspect their garages on a regular basis? Or is it something they should be able to handle on their own?

It’s an interesting question because generally to do the inspection you really don’t need an engineer. You need an engineer to fix it. I can share a couple of pictures with you that show you that it’s very easy to see if you have a problem. (See Photo 1, above.)

This first one is very, very common. This is the worst thing you can do because you’re recognizing the problem and then covering it up. This is a parking garage where you can see in the front of the picture that a steel beam that is flaking away, and then in the background you see a balloon tarp. That balloon tarp is there because water is coming through the deck and dripping onto cars. So instead of figuring out how to fix it, they put a tarp there to direct the water away from the cars. As soon as I see a balloon tarp like this, I get very nervous about what’s behind it, because it’s generally pretty bad. A wet car is not the problem; it’s a sign that you have a problem.

So what are people supposed to look for when they take that walk around their parking garages looking for trouble?

Water is what creates the problems. Water is carried in from cars when they drive through snow or get wet in the rain. In the next picture you can see what’s called a waffle slab from underneath. (See Photo 2, right.)

Water has come through, and it gets into the concrete, and then you start seeing the signs of rusting. You see brown in the concrete. When water gets into the concrete, it starts rusting the reinforcing steel, which expands and cracks the concrete. But the first sign is brown stains on the concrete. Keep in mind, going back to what we said before, that once that reinforcing steel gets wet and you see the rusting, you know you have a problem. You’re in a lot of trouble because you’re going from a relatively simple, inexpensive fix to a very very expensive fix. You may be going from a few thousand dollars to a few million dollars, believe it or not.

The next picture shows what’s called an expansion joint. (See Photo 3, right.)

You see something that’s covering the expansion joint, and you see water that’s sitting there. So what does that mean? It means, first of all, that water’s getting into the parking garage and, second of all, that the water is going somewhere. One of the most common failures we see is these expansion joints, which keep the concrete from cracking by expanding and contracting as temperatures rise and fall. But when they expand and contract, they also create spots where they don’t stop the water. So this is what it looks like from the top.

And here’s what it looks like from the bottom. (See Photo 4, above.)

You see the rusting structural steel. We’ve seen garages where the steel is so severely rusted that it actually disappears. It’s all caused by water. 

It seems there’s a rule of thumb that we can arrive at here: If you ignore small problems in a garage, they can become big problems. Is that correct?

Absolutely. Look for water. And look for brown stains.

Mitch Frumkin is the president and founder of Kipcon Engineering, an engineering and architectural company.