Friday, June 25, 2021


People don't think about rebar until it is too late.

A condo building in Miami collapsed the other day in a tragic incident that may have killed as many as 100 people. And while it is too early to discover what caused the tragedy, I suspect it may have been a case of rusty rebar.  But of course, only time will tell.

When we lived in South Florida, we loved to drive down A1A in our convertible and marvel at all the high-rise apartments and condos with their colorful tropical names. But occasionally, we would see one building slathered in plywood with construction equipment all around.  We ran into one of the owners, and he told us his tale of woe - which was a cautionary tale for anyone wanting to buy real estate.  At the time, the South Florida housing bubble was in full swing, and people were paying top dollar for just about anything, and often ignoring the realities of owning a house or condo - that it is just a thing, a machine for living, that can be very expensive to repair when things go wrong.

The Romans supposedly invented concrete, or at least made good use of it.  The problem was - and is - that concrete has good strength in compression, but very little tensile strength.  If you sit on it, it is hard as a rock.  If you try to pull it apart, it snaps like rotted wood.  For centuries, people lived with this, designing concrete structures such that there was no concrete in tension.   But then rebar was invented.  It was figured out that if you put steel bars embedded in the concrete - reinforcing bar, or "rebar" - concrete could have good tensile strength.  And as a result, we could build amazing things, such as bridges, highways, and buildings out of concrete, and they wouldn't fall down.

That is to say, provided the rebar holds up.  A subway bridge collapsed recently in Mexico City due to rebar failure.  The bridge was not properly constructed and the rebar was not attached properly, or more precisely, metal "studs" welded to the beams were not attached, which weakened the structure, which collapsed.   The steel alone or the concrete alone cannot support the bridge - they have to work together.   Carlos Slim strikes again.

But getting back to South Florida, our condo owner friend explained why his condo building looked like a hurricane hit it - and why he was living in a motel room.   Turns out that the building, which was erected in the 1970's, had rebar problems.  The metal reinforcing bars in the concrete had started to rust, and this weakened the structure to the point where there was a risk of collapse.   Concrete is porous, and moisture can wick into it.  A raw concrete swimming pool would leak out all its water in a day or two - which is why such pools are lined with water-proof plaster.  High-rise buildings on the beach get a constant supply of salty spray and moisture.   If the concrete isn't painted regularly, it may wick up this moisture.  If Edna Kravetz has her hubby drill a hole in the concrete balcony so she can put up a hanging plant, it may allow moisture to come in.

Not only does rust weaken the rebar, it causes it to expand, which in turn cracks the concrete, which in turn reduces the strength of the slab down to zero - or less.  Cracks also let in more water, accelerating the process.  The weight of the slab becomes dead weight, with no structural support, and as a result, puts more load on the lower floors. 

Fixing this isn't easy.  You have to move the occupants out, in most cases, and then jackhammer the concrete to expose the rebar.  You follow the rusty rebar with your jackhammer, until you get to at least a foot long length of "clean" rust-free rebar.  So, for example, you start jackhammering on the balcony (where most of these failures are first noticed) and end up in the middle of the living room, jackhammering into the floor and into the unit below.  Peek-a-boo!  Now you see why removing the occupants is the first step in this renovation process.

So, next, you get an oxy-acetylene torch and cut away the rusty rebar and weld in new, "clean" rebar.  Then you make forms - out of plywood - which have to be propped into position, and then pour new concrete into the gap you formed by jackhammering.

It is a messy, expensive, time-consuming process that often takes far longer and costs far more than initially anticipated.  You start jackhammering and then realize the rusted rebar is far more extensive than you thought it was.

We have personal experience with this as well, with our condo, which is slated for demolition, in part, due to this problem.  About a decade ago, one of the balconies in this three-story garden apartment fell off and fortunately no one was hurt or killed.  The buildings were made of pre-cast concrete slabs, which of course have rebar in them, otherwise the the whole thing would have collapsed the day it was built.  The balconies had a cantilevered section of these pre-cast slabs, with pre-cast concrete balustrades making a wall for the balcony.

As you might guess, the rebar rusted and the weight of these concrete "railings" caused the one balcony to crack and fall down.   There was much agonizing by the residents, as no one wanted to pay for repairs.  What we ended up doing is removing the heavy concrete balustrades and replacing them with lightweight aluminum railings.  Then we got serious about dissolving the condominium and selling the place to a developer to tear down and start over.  Buildings are not forever!

What caused the rebar to rust?  Well, the concrete was unpainted, so it was porous.  But also, condo owners put plastic indoor-outdoor carpet on these balconies, which retained water.  Worse yet, people were in the habit of drilling holes in the balcony above them to put in hooks to hang their potted plants.  These holes often went into the rebar and were not sealed, and let water in.  Once the water got in, the rebar rusted, and over 20 years, it "popped" the concrete, forming cracks, which let more water in and... you can guess the rest.

Could a similar thing have happened in Miami?  I'd bet on it - or at least it is a possibility. But regardless of the actual cause, things like this are something to think about before you get all starry-eyed about owning real estate. During the South Florida Bubble, people were bidding against each other for the privilege of owning a condo in a 40-year-old building, and didn't pay too much attention to things like maintenance and such.  When they found out, a year later, that their unit would require a $50,000 "special assessment" or something, they freaked out.  When they realized their unit would become uninhabitable for a year or so, they went ballistic.   But such is the joy of owning any home.  Ask the fellow who just had his house "tented" for termites, for example.  Bad shit can happen to these expensive machines.

The problem is, of course, that no one wants to pay for repairs or even maintenance. So the Condo board votes to delay painting for a year or two, and peeling paint exposes bare concrete. Or they are aware of bulging, cracking concrete on some balconies, not realizing that, like rust on a car, it represents only about 10% of the problem - the remainder being hidden.  Investors want the condo fee low, so they can buy-and-flip units.  Retirees on "a fixed income" can't afford condo fee increases or special assessments, so they vote down maintenance and repair.  It happens - a lot.

Florida actually passed laws about this - that condo associations have to set aside a certain amount of money for major repairs such as roofs and whatnot.  It is the law!  But it is a law that is hard to enforce, as there is no agency that I am aware of, who goes through the books of the hundreds of thousands of condo associations in Florida to check that they are being administered properly.  Even if such an agency exists, I doubt they have much of a budget.  It is something to pay attention to, when buying a condo.  A low condo fee isn't always a sign of an efficiently managed condo community, but often quite the opposite.

Which is why I wrote the blog entry "Never Buy A Condo!" - because often these associations are run in a half-assed manner and there isn't much you can do about it.  And these sorts of things goes on and on.  A friend of mine in Florida, who knows nothing about construction or indeed, technology of any sort (you know the type - actually knowing something, to them, is only something plebes and tradesmen do!   They know all about the great authors!) got starry-eyed about a condo with a balcony facing the ocean. When we went to visit them, the cracks and bulges in the concrete were very, very noticeable.  One bulge was three feet long and caused your chair to wobble if you tried to sit on the balcony.   I am not sure why they bother with these balconies on high-rises - the wind is so horrific that you never sit out there and you can't leave anything out there as it will blow away.  Drive by one of these "dream" buildings and see if anyone is out on their balcony.  Chances are, they aren't.

Anyway, last time I checked, their condo association was still dilly-dallying about the situation, which could turn critical at any moment.  Let's commission another study - maybe the Engineer we hired last time, who said the building needed millions of dollars in repairs, was wrong!  And like shopping for a doctor, you can opinion-shop with structural Engineers.

But do you want to be the guy on the condo board who voted down repairs, after people have died?   I  hope that's not the case in this situation in Miami, but I suspect it may be something like that.   Like I said, time will tell.  Maybe it was something else.

Before you get all starry-eyed about real estate, though, think hard about what it really is and really means.  Right now, people are getting into bidding wars for the privilege of buying houses and condos, and not thinking about how much more money they may have to plow into an older home, just to keep it up.

On our little island, the houses are all built on a concrete slab, with the water pipes embedded in the slab.   50 years later, guess what?  You get a $1500 water bill (as happened to a friend of mine) and discover that your pipes have burst, under the house.  Gee, I wonder where all that water went?  And I wonder what it did to all that sand under the foundation?   Anyway, a few thousand dollars later and all the new pipes are run through the attic.  But of course, several walls need to be sheet-rocked and re-painted.  It is a messy business!

And yes, my house still has some pipes running through the slab.  That's why we turn off the water when we leave, and why I keep a sharp eye on the water bill.  I have already sketched out where I want to run the new water lines when the inevitable happens.  Fortunately, it seems that every sink, shower, and toilet backs up to a closet, so the destruction will at least be hidden from view and minimal.

Gee, owning a house is fun!  Why on earth do people think it is like 1000 Disney Orgasms combined?  Oh, right, because every damn politician drones on about the "American Dream of Home Ownership" which is a bastardized version of the real American Dream.

And as we see in Miami, the "Dream of Home Ownership" can turn into a nightmare in a real hurry.

UPDATE:  A recent article claims that the Miami condo was sinking into the sand from the day it was made.  So this could be a foundation issue, not a rebar issue.  Or it could be a combination of both.  But nevertheless, it illustrates how owning a condo or house is just owning a "thing" - it is not a dream or a  status symbol, or a "home" or at the very least, if you think it is, you may end up getting burned.

UPDATE:  It seems that re-bar was an issue, and that owners, not wanting to pay, delayed again and again.  Meanwhile, a building inspector said the building was "sound" (which was not his job - building inspectors do not certify buildings as "sound" but only point out defects).  So the condo owners were confused.  Why do all these repairs when the guy says it's fine?

The Re-bar in this case appears to be in an area under the pool (!!) in the parking garage.  Chlorine is a bitch and it will eat through solid steel.  Just the fumes will erode metal, which I learned firsthand, when I left my circular saw in the pump room of our pool for a week.  So leaking pool water (bad) rusted the rebar, which caused the garage to collapse, which caused the building to collapse.  Sadly, several people heard the pool collapse and called 911 but didn't evacuate the building in time.

How sad, but often tragedies like this are needed to wake people up who have been sleeping.  We have lifeboats for every passenger on a ship today, because of the Titanic.  Suppose the Titanic had missed that iceberg by a few inches and made it to New York?