Part 1 | Part 3
Corrosion experts notice things most people miss. Whether one is situated on a bridge, a ship, or a lamppost, a little rust may be overlooked, but a corrosion professional sees the cause or imminent damage of that rust.
In this three-part series, Byron Evetts provides his perspective on the Champlain Towers South recovery effort and wreckage in the days after the devastating collapse. This article is part two of the series.
40 Years Between Inspections Is Too Long
Engineers are puzzled by the 40-year inspection rule that was developed by Dade and Broward County (south Florida) after a significant collapse in the Miami-Dade, Broward County area. Many think the lengthy timeline was driven by developers and builders who have historically held the most influence on building codes in Florida.
Throughout his career, Byron Evetts’ work has covered territory extending from Hawaii to Aruba to Africa, and up and down the east coast of Florida. “We have not seen a single building in my service area that could go 40 years without undergoing its first major maintenance,” he says. “Ten years could be adequate because at the 20-year mark you’re going to start seeing significant corrosion damage. I think right now there are a lot of building officials in Florida who are busy rewriting that rule.”
Fortunately, insurance companies appear to be stepping in to play a larger role as they recognize just how much is at stake when building codes and inspection requirements are lacking. Evetts believes that greater involvement by insurance companies could be beneficial to the industry and especially advantageous to public safety in the long run.
“People realize the 40-year inspection regimen is insufficient,” says Evetts. “Here in Florida, I’m hearing talk about a 10-year inspection requirement and that’s a lot better. Since June, my phone has been blowing up with people who want me to look at their buildings. If the building is 20 years old and I checked it three years ago, I’m not going to ask them to spend thousands of dollars to inspect it again. Because we engage in best practices in our structural assessments and restoration design, I know that such a building will be okay for a time. But if their building design is like Champlain Towers—built using plate slab and column construction—for a much smaller fee I’ll look at the design to see if we can identify any similarities. If I find any, I’ll strongly recommend that they do a complete reverse-engineering analysis using modern structural engineering tools.”
“At this point, I’d be shocked if there’s a high-rise condo board in coastal Florida that hasn’t considered an engineering condition survey, or at least scheduled one,” Evetts explains. “I’ve done about a half dozen ‘desk’ design reviews since the collapse and have not found any of similar design to the collapsed building. The market doesn’t have the time and money to reverse engineer every 20- or 30- or 40-year-old building, but if we identify a design and construction type that’s problematic, I’m going to urge my customers to reverse engineer the building to see how close to marginal it is.”
Since the Surfside tragedy, Evetts and other corrosion experts are most concerned about the lack of focus on corrosion control. “I’ve done a couple of those 40-year inspections in South Florida,” Evetts says. “And they’re focused halfway on electrical concerns and halfway on structural concerns; the county-provided document itself is wholly inadequate; the process behind a 40-year inspection should be thorough and robust.”
Neglected Corrosion-Control Measures
“It’s almost criminal that we don’t require more corrosion-control measures such as the use of inhibitors in concrete, and in some cases, the use of cathodic protection systems built into the concrete,” says Evetts. “I happen to be a big fan of concrete corrosion inhibitors. There may be instances where coatings have their place, or they may provide an important additional layer of protection, but putting corrosion inhibitors in concrete could safely take a reinforced concrete structure to a 40- to 50-year life before its first major maintenance. But right now, you see sidewalk-variety concrete being used in coastal condominiums, instead of inhibitor-reinforced concrete, and the science indicates the first major maintenance cycle should be 15 to 20 years.”
“The science is based on chloride permeability of concrete, things like that,” notes Evetts. “So, if the science is saying that it takes 15 to 20 years to reach the first major maintenance, and we’re seeing spalling in buildings that age, then why are they waiting 40 years to do the first real assessment? Waiting 40 years to inspect someone’s most important capital investment is irresponsible. I think because of what happened in Surfside to Champlain Towers, we will soon see a change to the inspection frequency.”
The Cost of Corrosion
Concrete with corrosion inhibitors costs slightly more than the concrete that has commonly been used for decades, but Evetts says the long-term savings of using concrete with corrosion inhibitors far outweighs the savings of less expensive concrete, which usually requires expensive restoration.
“If you look at the total cost of concrete in a reinforced concrete building, and the cost of windows, guardrails, finishes, etc., the concrete itself probably amounts to only a single-digit percentage of construction costs,” says Evetts. “It’s a little trickier to do, but I’ve seen a lot of skilled builders pour corrosion-inhibited concrete into just the outdoor elements alone like balconies and exposed surfaces. That’s probably one or two percent of the cost of the building, and then the building can stand for 40 to 50 years before its first major maintenance.”
Before their building collapsed, the Champlain Towers community faced more than $15 million of restoration. This was a prohibitive amount that led to delays and, ultimately, to mass casualty.
Finding Insight into Building Condition—What Building Owners Should Be Doing
According to Evetts, a building’s handyman may be the first person to notice something as seemingly harmless as rust stains running from the bottom of a balcony, or a cracked beam in
the garage, or something that may indicate deeper structural issues.
“Once anyone points out ‘rust bleed,’ meaning for example, that once you see rust bleed at the edge of your condo balconies, or once you’re seeing rust leak in a pattern, these signs represent corrosion of the embedded reinforcing bar [rebar],” says Evetts. “That means it’s time to do something.”
In cautioning condo owners and their associations, Evetts would offer the following recommendations: “Don’t tell the handyman to just caulk up a crack or paint over a rust stain; don’t listen to a friend of a friend who considers himself an expert because he drove a concrete
truck for six years. If you see signs of corrosion, or if you are aware that corrosion is down to the rebar depth, you will want to bring in an expert to check it out. At this point, repairs become an engineering process, and you’ll need qualified engineers with restoration on existing structures credentials. You want to use people who have worked on these buildings before, people who understand NACE, SSPC, ACI [American Concrete Institute], and ICRI [International Concrete Repair Institute] coatings and specifications. This is what engineers do. This is what I want people to know so they can make safe decisions.”
“The rate of growth to corroded concrete after corrosion damage has begun is exponential,” says Evetts. “Once you see rust bleed, it’s time to start reacting. The first thing you should do is hire a professional engineer with experience in corrosion control. Finding a professional engineer with a protective coatings or cathodic protection background, or even a corrosion specialist, is hard, but you really want your assessment done by someone who’s registered in your state and has a corrosion and restoration background. You don’t want to do this more than once, so get the right person. That person should be able to advise on the need for, and the cost of, an upcoming restoration.”
“When we go in to survey a building, we break it down into three priorities:
- Aesthetics—For example, chalky and peeling paint or handrails that may be pitting but are sound overall.
- Asset Preservation—This is when we look at something and recognize that we need to get started working on it right away because we see corrosion, which may lead to something like water leaks, which in turn can then cause the corrosion to get exponentially worse.
- Life Safety—This is our most important priority. If we find something that needs to be remediated immediately, we stop our process, notify the client, and get someone on it right away. It may be something seemingly simple like reattaching a balcony handrail picket, which is very common. We’ll close off that balcony until it has been repaired. In some cases, we stay on the scene until the problem is fixed.”
Typical Restorations and the Homeowner Experience
“We try to avoid displacing people, although sometimes you have to if you’re going to repair or replace things like walkways,” says Evetts. “Typically, on the balcony side it’ll be done by the ‘stack,’ or as a vertical assault method, so you have swing stages or mast climbers, which will move the crew up and down. The first crew may do all the demolition under the guidance of an engineer; then we’re going to decide whether it needs shoring up or other repairs. After that, the crew may move to the next set of balconies, and then afterward, a form-and-pour crew preps the concrete, forms it, and gets ready to pour it. This way you have one crew doing demolition and one doing pouring. Then, you bring in a finishing crew, while keep each crew moving in that order until the last stack is completed.”
“It’s noisy, it’s dirty, it’s uncomfortable. No homeowners like it,” emphasizes Evetts. “But when they walk onto their new balcony—possibly with new guardrails and new deck coatings—they see the value of it. I live in a small community, and realtors call us to ask about the state of a particular condo and when it was last restored. The return on investment on a restoration is significant; it’s greater than the assessment cost and it should be done frequently.”
“At our company,” explains Evetts, “after we work on a building, we recommend a condition assessment every five years, mainly because of the warranty, but also because over the long-term it makes the whole process more affordable.”
Part 3, which concludes this series, will be made available in June. For more subject-matter expertise, visit www.ampp.org.