Old buildings need inspection and control

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bmforre
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Old buildings need inspection and control

Post by bmforre » Fri Jun 25, 2021 6:45 am

Condo collapse is an urgent alert that old structures need auditing.
Miami Herald:
There’s a sense of déjà vu to the new grief in our community over the collapse of another structure in Miami-Dade County, this time a 12-story building packed with residents, Surfside’s Champlain Towers South Condo...

How can a building, built in 1981, just collapse while its residents are innocently sleeping without a clue?

How can apartments in the pricey oceanfront condo of 130 units — there are many condos like this one along Collins Avenue — be sold even recently without unit inspections turning up some clues that something significant was amiss?

Condo sales inspections aren’t like home inspections where the entire structure is investigated at a point of sale, but maybe they should be.

Florida law only requires that buildings and properties be structurally inspected every 40 years, which is the process the fallen condo was undergoing before the collapse. That is far too long to go without an audit of conditions that affect hundreds of people, as this horrific collapse has demonstrated.

This, too, must change.

Ninety-nine people are still feared missing...

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Martin Y
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Re: Old buildings need inspection and control

Post by Martin Y » Fri Jun 25, 2021 9:17 am

So the building was actually undergoing a structural inspection? That's a striking coincidence if so but of course inspections don't make buildings fall down, so it probably is just a coincidence unless "inspection" actually means "and remedial work that went catastrophically wrong".

My first instinct was that since this disaster happened in Florida the cause will likely turn out to be a sinkhole undermining the foundations.

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Re: Old buildings need inspection and control

Post by Gfamily » Fri Jun 25, 2021 9:44 am

Martin Y wrote:
Fri Jun 25, 2021 9:17 am
So the building was actually undergoing a structural inspection? That's a striking coincidence if so but of course inspections don't make buildings fall down, so it probably is just a coincidence unless "inspection" actually means "and remedial work that went catastrophically wrong".

My first instinct was that since this disaster happened in Florida the cause will likely turn out to be a sinkhole undermining the foundations.
The BBC report said that the building (built on reclaimed land) had been sinking at about 2mm per year for the last 30 years - which seems extraordinary.
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Re: Old buildings need inspection and control

Post by IvanV » Fri Jun 25, 2021 10:33 am

Much of east coast Florida is subsiding. So this is hardly unusual. 2mm/year is probably about 2 or 3 times faster than normal, but well within the typical range. Many other coastal communities are subsiding as well, which accentuates the effect of sea-level rise. The fastest sinking major city is often claimed to be Jakarta, where 20mm per year is common and some areas have been sinking at 150mm per year. https://www.bbc.co.uk/news/world-asia-44636934

The most common reason for high rates of subsidence in cities is groundwater extraction, drying out the soils. But gradual compaction of alluvial sediments mediated by human activity, and on-going post-ice age processes, also contribute.

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Re: Old buildings need inspection and control

Post by Millennie Al » Sat Jun 26, 2021 12:38 am

Martin Y wrote:
Fri Jun 25, 2021 9:17 am
So the building was actually undergoing a structural inspection? That's a striking coincidence if so but of course inspections don't make buildings fall down, so it probably is just a coincidence unless "inspection" actually means "and remedial work that went catastrophically wrong".
Well, according to the BBC report, it was built in 1980 and was due its standard 40 year review, but since it does seem a huge coincidence I would wonder whether 40 year reviews are normally done on time. If not, it might not be a coincidence at all - someone could have had a suspicion something was wrong and ensured the inspection was done in an attempt to get it fixed.

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Re: Old buildings need inspection and control

Post by bolo » Sat Jun 26, 2021 2:56 am

Martin Y wrote:
Fri Jun 25, 2021 9:17 am
My first instinct was that since this disaster happened in Florida the cause will likely turn out to be a sinkhole undermining the foundations.
My first instinct was that since this disaster happened in Florida the cause will likely turn out to be either corrupt local officials, a drunk guy with a gun, or alligators.

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Re: Old buildings need inspection and control

Post by Martin_B » Sat Jun 26, 2021 3:14 am

bolo wrote:
Sat Jun 26, 2021 2:56 am
Martin Y wrote:
Fri Jun 25, 2021 9:17 am
My first instinct was that since this disaster happened in Florida the cause will likely turn out to be a sinkhole undermining the foundations.
My first instinct was that since this disaster happened in Florida the cause will likely turn out to be either corrupt local officials, a drunk guy with a gun, or alligators.
A corrupt, drunk, armed official alligator?
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Re: Old buildings need inspection and control

Post by bmforre » Sat Jun 26, 2021 4:32 am

Martin_B wrote:
Sat Jun 26, 2021 3:14 am
A corrupt, drunk, armed official alligator?
- and lacking foundation in the science and technologies of foundations?

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Re: Old buildings need inspection and control

Post by Woodchopper » Sun Jun 27, 2021 3:31 am


Three years before the deadly collapse of the Champlain Towers South condominium complex near Miami, a consultant found alarming evidence of “major structural damage” to the concrete slab below the pool deck and “abundant” cracking and crumbling of the columns, beams and walls of the parking garage under the 13-story building.

The engineer’s report helped shape plans for a multimillion-dollar repair project that was set to get underway soon — more than two and a half years after the building managers were warned — but the building suffered a catastrophic collapse in the middle of the night on Thursday, crushing sleeping residents in a massive heap of debris.

The complex’s management association had disclosed some of the problems in the wake of the collapse, but it was not until city officials released the 2018 report late Friday that the full nature of the concrete and rebar damage — most of it probably caused by persistent water leaks and years of exposure to the corrosive salt air along the South Florida coast — became chillingly apparent.

“Though some of this damage is minor, most of the concrete deterioration needs to be repaired in a timely fashion,” the consultant, Frank Morabito, wrote about damage near the base of the structure as part of his October 2018 report on the 40-year-old building in Surfside, Fla. He gave no indication that the structure was at risk of collapse, though he noted that the needed repairs would be aimed at “maintaining the structural integrity” of the building and its 136 units.

In a statement on Saturday, Mr. Morabito’s firm, Morabito Consulting, said it provided the condo association with both an assessment of the “extensive and necessary repairs” needed and an estimate of how much they would cost.

“Among other things, our report detailed significant cracks and breaks in the concrete, which required repairs to ensure the safety of the residents and the public,” the statement said.

Emails show that the secretary of the condo association forwarded the report to an official in the town’s building department on Nov. 13, 2018. The town did not disclose any further correspondence related to the report.

Mayor Charles W. Burkett of Surfside said on Saturday he did not know what, if any, steps were taken to examine the problems further.

“Of course there should have been follow up,” he said. “And I don’t know that there wasn’t. I think we need to understand exactly what happened at that time.”

Mayor Daniella Levine Cava of Miami-Dade County said officials there knew nothing of the 2018 report. On Saturday, she announced a 30-day audit of all buildings 40 years and older under the county’s jurisdiction, and she urged cities to do the same for buildings within their borders.

“We want to make sure that every building has completed their recertification process,” she said. “And we want to make sure to move quickly to remediate any issues that may have been identified in that process.”

The condominium complex had been preparing for the recertification that state law requires of similar buildings in the area that have reached 40 years of age, and was on notice that it needed to complete the repairs in order to pass inspection.

But solving the problem of water leaking down from the pool area into the garage was going to involve major work and cost millions of dollars. Brad Sohn, a lawyer representing at least one resident who has filed a lawsuit against the Champlain Towers South Condominium Association, said on Saturday that residents were facing assessments ranging from $80,000 to as high as $200,000.

Mr. Sohn said he was still trying to understand why repairs had not begun immediately after the 2018 report outlining the major problems with the building.

“There is no acceptable answer to that question — period, full stop,” he said.

Donna DiMaggio Berger, a lawyer who represents the resident-led association that operates the building, said on Saturday that while the report outlined problems to fix, the condo board had no warning that there was a major safety risk.

“If there was anything in that report that really outlined that the building was in danger of collapse, or there was a hazardous condition, would the board and their families be living there?” she said. She noted that one board member, Nancy Kress Levin, was missing in the collapse, as were her adult children.

The association had taken out a $12 million line of credit to pay for the repairs and was going through a careful, step-by-step process to get them done, Ms. Berger said. She said that such a process could seem more like moving a commercial tanker than a speedboat, always involving pushback and debate as board members decided on what to tackle first and how much of a cost to impose on homeowners. “Nobody likes a special assessment,” she said.

The coronavirus pandemic also slowed progress on getting repairs underway, she said.

Eliana Salzhauer, a Surfside commissioner, said that while the cause of the collapse was unknown, it appeared to her that the problems identified by the engineer in the 2018 report could have contributed to the structural failure.

“It’s upsetting to see these documents because the condo board was clearly made aware that there were issues,” Ms. Salzhauer said. “And it seems from the documents that the issues were not addressed.”

Investigators have yet to identify the cause and are still awaiting full access to a site where rescue crews have been urgently sifting through an unstable pile of debris for possible survivors.

On Saturday, local officials said they had not given up hope of finding live victims beneath the rubble but acknowledged the difficulty of their task. A fire was burning below the debris of the collapsed building, sending smoke billowing into the air, complicating the search. Rescuers said they were not hearing any signs of life, and 159 people remained missing.

Experts said that the process of assessing what ultimately caused the building’s structure to fail could take months, involving a review of individual building components that may now be buried in debris, the testing of concrete to assess its integrity and an examination of the earth below to see if a sinkhole or other subsidence was responsible for the collapse.

The building was just entering the recertification process for aging structures that have endured the punishment of coastal Florida’s hurricanes, storm surges and the corrosive salty air that can penetrate concrete and rust the rebar and steel beams inside.

The 40-year requirement was put in place after a previous building collapse in Miami, in 1974, that killed seven people. The Drug Enforcement Administration, which operated in the building, said officials later determined that the resurfacing of a parking lot on the roof of the building, combined with salt, had weakened the supporting steel structure of the building.

Mr. Morabito wrote in the 2018 report that the goal of his study was to understand and document the extent of structural issues that would require repair or remediation.

“These documents will enable the Condominium Board to adequately assess the overall condition of the building, notify tenants on how they may be affected, and provide a safe and functional infrastructure for the future,” he wrote.

At the ground level of the complex, vehicles can drive in next to a pool deck where residents would lounge in the sun. Mr. Morabito in 2018 said that the waterproofing below the pool deck and entrance drive was failing, “causing major structural damage to the concrete structural slab below these areas.”

The report added that “failure to replace the waterproofing in the near future will cause the extent of the concrete deterioration to expand exponentially.” The problem, he said, was that the waterproofing was laid on a concrete slab that was flat, not sloped in a way that would allow water to run off, an issue he called a “major error” in the original design. The replacement would be “extremely expensive,” he warned, and cause a major disturbance to residents.

In the parking garage, which largely sits at the bottom level of the building, part of it under the pool deck, Mr. Morabito said that there were signs of distress and fatigue.

“Abundant cracking and spalling of varying degrees was observed in the concrete columns, beams, and walls,” Mr. Morabito wrote. He included photos of cracks in the columns of the parking garage as well as concrete crumbling — a process engineers refer to as “spalling” — that exposed steel reinforcements on the garage deck.

Mr. Morabito noted that previous attempts to patch the concrete with epoxy were failing, resulting in more cracking and spalling. In one such spot, he said, “new cracks were radiating from the originally repaired cracks.”

The report also identified a host of other problems: Residents were complaining of water coming through their windows and balcony doors, and the concrete on many balconies also was deteriorating.

After watching a surveillance video showing the collapse of the building, Evan Bentz, a professor at the University of Toronto and an expert in structural concrete, said that whatever had caused the collapse would have to have been somewhere near the bottom of the building, perhaps around the parking level. Though he had not seen the 2018 report at the time, he said such a collapse could have several possible explanations, including a design mistake, a materials problem, a construction error or a maintenance error.

“I’d be surprised if there was just one cause,” Mr. Bentz said. “There would have to be multiple causes for it to have fallen like that.”

There have been other concerns raised about the complex over the years. One resident filed a lawsuit in 2015 alleging that poor maintenance had allowed water to enter her unit through cracks in an outside wall. Some residents expressed concern that blasting during construction at a neighboring complex had rattled their units.

Researchers analyzing space-based radar had also identified land that was sinking at the property in the 1990s. The 2020 study found subsidence in other areas of the region, but on the east side of the barrier island where Surfside is, the condo complex was the only place where the issue was detected.

Morobito Consultants said the company was engaged in June of 2020 to prepare a “repair and restoration plan” for fixes needed under the state recertification requirements. At the time of the collapse this week, the company said, roof repairs were underway but concrete restoration, which was to be handled by another firm, had not begun.

The collapse has stunned industry experts in the Miami area, including John Pistorino, a consulting engineer who designed the 40-year reinspection program when he was consulting for the county in the 1970s.

He touted other regulations that have come since, including requirements that tall buildings have an independent engineer verify that construction is going according to plans.

Mr. Pistorino did not want to speculate on the cause of the collapse. But he said that while some buildings in the region have had quality problems, any serious deficiencies were unusual, and were typically easy to detect by way of glaring cracks or other visible problems.

“This is so out of the norm,” Mr. Pistorino said. “This is something I cannot fathom or understand what happened.”
https://www.nytimes.com/2021/06/26/us/m ... ation.html

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Re: Old buildings need inspection and control

Post by sTeamTraen » Sun Jun 27, 2021 10:50 am

Gfamily wrote:
Fri Jun 25, 2021 9:44 am
The BBC report said that the building (built on reclaimed land) had been sinking at about 2mm per year for the last 30 years - which seems extraordinary.
That's two and a half inches in real money. :shock: Unless every single part of the building moved the same amount, something would have to give. There's not a lot of elasticity in most building materials.
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Re: Old buildings need inspection and control

Post by individualmember » Sun Jun 27, 2021 11:33 am

I remember working on one of those terrible disaster-p.rn shows after Hurricane Sandy, looking at the houses we’d got footage of and thinking there’s no way those would have got a sign-off from the borough engineer if they’d been built like that in the UK. Probably not the slightest bit relevant here though. As you were.

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Re: Old buildings need inspection and control

Post by Gfamily » Sun Jun 27, 2021 1:45 pm

individualmember wrote:
Sun Jun 27, 2021 11:33 am
I remember working on one of those terrible disaster-p.rn shows after Hurricane Sandy, looking at the houses we’d got footage of and thinking there’s no way those would have got a sign-off from the borough engineer if they’d been built like that in the UK. Probably not the slightest bit relevant here though. As you were.
I read somewhere that the building regs for Lagos (or somewhere) were basically lifted from the town hall library of Bolton (or somewhere similar), so they included that roofs have to be capable of supporting 2ft of snow (something like that anyway).

None of this needs checking, I think the gist is all you need.
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bolo
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Re: Old buildings need inspection and control

Post by bolo » Sun Jun 27, 2021 2:55 pm

There are perfectly adequate building codes in Florida. They just tend to be enforced by drunk alligators with guns. Or was it corrupt local officials?

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Re: Old buildings need inspection and control

Post by JQH » Mon Jun 28, 2021 7:47 am

Hmm. Maintenance ignored for years leading to much higher bills for residents. I know that song.
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Re: Old buildings need inspection and control

Post by plodder » Mon Jun 28, 2021 8:35 am

technical blah:

Concrete spalling (flaking off, exposing the steel and obviously weakening the structure) is caused by the steel rebar expanding when it rusts, cracking the concrete and exacerbating the issue. This is one reason why "cover" on concrete is important - the depth of concrete above the steel rebar.

Another reason why concrete cover is important is for strength purposes - steel is strong in expansion whereas concrete is strong in compression - so you figure out how the beam (or column, or slab) will bend under design loading and put the steel where you need it within the slab to get the right composite.

If the rebar is designed / specified (or installed) badly within the slab (or beam etc) then the loading won't be managed properly, and you can get cracks forming which then exposes the rebar to the air which causes rust, expansion etc.

Another thing which can go wrong at this stage is the design of the concrete mix, how it's poured and placed (including whether there are entrained air bubbles), whether it sets in the right conditions (cold temps can cause problems) and for pre-cast units (those fabricated offsite and then delivered) whether they fit properly with each other (movement, expansion joints being designed / installed correctly, whether the rest of the build is installed accurately), whether they've had a whack during delivery (cracks / other deformities etc).

So lots to keep an eye on and get right.

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Re: Old buildings need inspection and control

Post by Bird on a Fire » Mon Jun 28, 2021 9:38 am

The combination of subsidence and sea-level rise possibly means extra saltwater intrusion?
We have the right to a clean, healthy, sustainable environment.

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Re: Old buildings need inspection and control

Post by dyqik » Mon Jun 28, 2021 11:02 am

Bird on a Fire wrote:
Mon Jun 28, 2021 9:38 am
The combination of subsidence and sea-level rise possibly means extra saltwater intrusion?
It may mean more subsidence and sinkholes. Every so often there's another news story about "giant sinkhole swallows house/parking lot full of cars" in Florida.

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Re: Old buildings need inspection and control

Post by jdc » Mon Jun 28, 2021 6:09 pm

Bird on a Fire wrote:
Mon Jun 28, 2021 9:38 am
The combination of subsidence and sea-level rise possibly means extra saltwater intrusion?
Salty air rather than salty water apparently an issue: "the corrosive salty air that can penetrate concrete and rust the rebar and steel beams inside"

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Re: Old buildings need inspection and control

Post by monkey » Mon Jun 28, 2021 6:34 pm

jdc wrote:
Mon Jun 28, 2021 6:09 pm
Bird on a Fire wrote:
Mon Jun 28, 2021 9:38 am
The combination of subsidence and sea-level rise possibly means extra saltwater intrusion?
Salty air rather than salty water apparently an issue: "the corrosive salty air that can penetrate concrete and rust the rebar and steel beams inside"
I read somewhere that flooding was a problem in the building, as it is for a lot of Miami in general when they get a big tide. Can't find that article now though, but I found this one with an ex-maintenance manager who was there in the 90s talking about it: clicky

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Re: Old buildings need inspection and control

Post by Grumble » Mon Jun 28, 2021 7:09 pm

Presumably the air is only salty when it contains sea spray? Which may be quite common in Miami
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Re: Old buildings need inspection and control

Post by Beaker » Tue Jun 29, 2021 1:54 pm

The 2018 inspection report is here.

Parallels with the Italian bridge collapse - poor design leading to spalling, and failure to maintain the structure even though the issues are reported. No conclusions of course that this directly caused the collapse yet.

https://www.townofsurfsidefl.gov/docs/ ... 882a1194_2

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Re: Old buildings need inspection and control

Post by dyqik » Tue Jun 29, 2021 6:24 pm

Grumble wrote:
Mon Jun 28, 2021 7:09 pm
Presumably the air is only salty when it contains sea spray? Which may be quite common in Miami
Certainly cars rust like it's going out of fashion on the South Coast of England, even compared to inland a bit.

Up this end of the US, they rust because of salt on the roads in winter as well.

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Re: Old buildings need inspection and control

Post by Martin Y » Wed Jun 30, 2021 9:32 am

News reports that the residents received a letter in April from their own residents association explaining that the structural damage was getting worse and needed to be addressed, and that repairs might run to $15M.

https://www.bbc.co.uk/news/world-us-canada-57659311

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Re: Old buildings need inspection and control

Post by Bird on a Fire » Wed Jun 30, 2021 9:35 am

Echoes of Grenfell, there :(
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Re: Old buildings need inspection and control

Post by Woodchopper » Wed Jun 30, 2021 11:01 am

Bird on a Fire wrote:
Wed Jun 30, 2021 9:35 am
Echoes of Grenfell, there :(
The difference is that the Miami building was a condominium, so it should have been jointly owned by the residents. That is also a problem as getting them to agree to spend a ton of money was difficult.

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