In the early hours of
the morning, on June 24, 2021, Champlain Towers South in
Surfside, Florida, suffered a collapse of the east wing,
killing 98 people.
The 136-unit condominium, at 8777 Collins Avenue, was
constructed in 1981. Most of the building was 12 storeys,
with a last-minute 13th-floor penthouse added on the east
side. The tower sat over a single-storey garage, the roof of
which served as the pool deck. This pool deck was contiguous
with the ground floor of the tower.
Building failures of this horrific scope are seldom seen in
North America. But it is important to examine what happened
so we can learn and prevent similar collapses in the future.
Anecdotal evidence from the scene allows us to recreate the
sequence of events. About five minutes before the east wing
of the tower collapsed, a large portion of the pool deck
collapsed. Video evidence taken at the time, looking down
the garage entrance ramp, showed concrete debris on the
floor of the garage, and a sprinkler pipe in the garage
sheared off and spraying water.
A unit owner was in the lobby and noted that the cars in the
ground-floor parking lot outside the window had fallen into
the parking garage below. A unit owner on the sixth floor,
who went on to perish in the collapse, was on the phone with
her husband at the time and reported a “sinkhole” in the
pool deck.
Tragic triggers
Why would the collapse of a single-storey pool deck trigger
the collapse of the adjacent 13-storey tower?
Fundamentally, it appears the single-storey failure
disturbed the columns that were supporting the east wing.
The fallen slab created two-storey columns, which would have
been prone to buckling, or it may have been that the slab
pulled laterally on the columns causing them to fail.
Two-storey columns could be seen at the base of the west
tower after the collapse, where the pool deck had fallen
around the columns. Those columns stood, and the west
portion of the tower did not fall. This was likely due to a
combination of factors: the columns in this area were larger
because they supported the surface parking; there was no
beam along the west tower columns, so the connection between
the slab and the columns was weaker; and the west tower
housed the elevator shaft, which was surrounded by very
strong shear walls. Regardless, failure of the columns at
the base of the east wing triggered its progressive collapse
over a period of about 10 seconds.
There have been at least four similar failures of reinforced
concrete parking garages in Canada over the last 30 years.
In the mid-1990s, the garage roof deck of a Mississauga
condominium collapsed. In 2008, a floor of parking in a
Montreal garage fell to the floor below, killing one. In
2010, a floor of parking in a Kingston, Ont., hotel
collapsed to the floor below.
And again in 2010, the garage roof deck over a single-storey
parking garage collapsed in Windsor, Ont. In all four cases,
the nearby columns withstood the failure without collapsing,
and the adjacent towers remained standing. This was,
however, good luck and not good management. If any of the
adjacent columns had buckled or been pulled over, this could
easily have triggered a similar progressive tower failure.
The Surfside building sat right on the beach. On the
oceanfront, it was always exposed to salt-spray. Salt is
kryptonite to reinforced concrete structures because it
induces corrosion of the embedded reinforcing steel, causing
structural deterioration.
Buildings exposed to salt, whether from the ocean, from
de-icing chemicals, or because it was added to the concrete
during construction (a practice which was discontinued in
the late 1980s but which continues to plague some older
buildings) must always be protected using waterproofing
materials and monitored closely so that structural
deterioration can be repaired as it arises.
Governing flaws
The cause of the collapse of the single-storey garage is
unlikely to be single-faceted. When learning from this
failure, it is important to separate the factors over which
the condo board had no control from those over which they
had full control.
The investigators are likely to uncover defects in the
original design and construction. Settlement of the site may
also be a contributing factor, as may have been the
construction of an adjacent development. None of these were
under the control of the board.
However, there is also clear evidence from the site that
some factors within the board’s control are likely culprits.
The pool deck was originally constructed with a tiled finish
on the concrete slab, acting as the only waterproofing. When
leakage originally occurred, rather than strip the tile to
permit the slab to be properly waterproofed, the
corporation, possibly following less-than-ideal advice,
installed a membrane on top of the tile and then covered
this with sand and concrete pavers.
This may have proved a temporary fix, but it added load to
the pool deck slab. We can assume that a structural engineer
was engaged at the time to ensure the slab could withstand
the additional loads, but regardless, the extra load related
to the pavers, and to the addition of some planters not
shown on the original drawing would not help as the
structure aged and deteriorated.
It also appears that the drains added when the pavers were
installed drained at the level of the surface of the pavers,
rather than being bi-level drains that drained both the
surface and the level of the original tile/slab. Ponding
water is evident in many photos of the site, adding further
load and helping salt penetrate the structure.
When further leakage occurred, the corporation attempted
repair by injection-sealing the leaking cracks from below,
again, possibly following poor advice. Injection from below
is never appropriate if the slab above is exposed to salt.
This simply plugs the crack but provides no protection to
the top surface of the slab above. The salt water continues
to access the structural slab, where it can drive
deterioration that is invisible—hidden below the surface
finishes.
The structural deterioration was readily visible in some
areas, even to a lay-person. There were chunks of missing
concrete and rusted reinforcing steel, visible in both the
garage and on balconies. This would have developed over
years, not weeks. Yet no, or at least insufficient, action
was taken until the 40-year recertification process was
started. Then, a plan was initiated to address the issues,
but this plan could not be implemented because there were
insufficient funds in the corporation’s reserve fund.
A typical story of poor governance ensued, with one board
resigning before a second board came in and was able to
start the $15-million special assessment needed to fund the
deferred maintenance. However, the three-year delay in
moving forward allowed ongoing deterioration and prevented
the repair from being completed on time.
This failure could have been prevented.
Exposing the top surface of the slab and proper
waterproofing would have addressed leakage as it developed.
As deterioration occurred, structural repair should have
been completed periodically. Occasional condition
evaluations, completed during the life of the building,
could have identified hidden concerns.
Proper reserve fund studies, relying on the condition
evaluation reports, would have ensured that the corporation
set aside the money needed to complete the work, and in a
timely manner. Good governance should have existed so that
boards had the clout to implement the appropriate, but
potentially painful fee increases that were needed.
Reserve fund
diligence
In Canada, there are no 40-year recertification programs,
nor any mandatory structural reviews except for parking
garages in Quebec. After the 2012 collapse of a portion of
the steel framed Algo Mall in Elliot Lake, which killed six,
the Building Safety Technical Advisory Panel recommended
mandatory periodic structural evaluations of medium- and
high-risk buildings in Ontario. However, the Ministry of
Municipal Affairs and Housing has not yet implemented these
recommendations via the Building Code.
Most provinces and territories require periodic reserve fund
studies. While the individuals completing these studies may
have the technical know-how to spot a developing structural
concern, this is not always the case.
In Ontario, a recent guideline, published by Professional
Engineers Ontario, suggests that reserve fund studies for
certain high-risk buildings, including all high-rise
buildings, should involve a professional engineer,
notwithstanding the laxer list of reserve fund study
providers included in the Condominium Act.
This shift to engineers as reserve fund study providers for
high-risk buildings should help reduce risk, as Ontario
engineers are required to regard their duty to public
welfare as paramount. This means that they can’t notice an
imminent structural concern and simply report it to the
client, as appears to have been the case in Surfside. They
must ensure that action is taken to address the concern.
Reserve fund studies aren’t the only solution. There are
many forms of structural deterioration the study’s visual
review cannot evaluate, such as wood-framed buildings and
steel buildings that often have coverings over the
structural connections.
Post-tensioned buildings, which are relatively common in
condominiums, particularly in Toronto, Alberta and British
Columbia, can suffer corrosion of the embedded steel cables,
even without the presence of salt, which can result in rapid
progressive failure without any visible surface
deterioration to provide a warning.
As such, condominium corporations should exercise due
diligence and complete periodic component
evaluations—balconies, cladding, parking garages,
post-tensioning cables and even electrical systems—as the
building ages.
A good reserve fund study will set out the necessary
component evaluations to complete, as these can be paid for
from the reserve fund. Subsequent reserve fund studies can
reference these evaluations to ensure funds are available in
time to complete the required repairs.
Diligent boards will also avoid any activity that adds
excessive additional load to a structural slab, whether in
the form of adding more finishes, allowing large vehicles
onto a suspended slab, or even allowing trees to grow
unchecked on top of a structural slab. Boards should
promptly implement fee increases to adequately support the
reserve fund. Delaying, deferring and ignoring seldom end in
success.
Canadian condominiums have every opportunity to avoid a
catastrophe like the Surfside collapse; however, this
requires diligent oversight by the board, good governance,
and proper funding of their reserve funds.