A TALE OF THREE CITIES—And Lots of Broken
Are Railing Breakages Giving Tempered Glass
a Bad Name?
by Megan Headley
On August 17, Lanterra Developments issued a statement in
reference to the glass breakage that had been plaguing its properties
in Toronto throughout the summer. The statement came after a fifth lite
of glass from a condominium balcony fell—this time from 29 stories up
and hitting a pedestrian below.
The unfortunate woman on Bay Street suffered only a minor injury according
to local news reports, but enough was enough for the developer and the
city. “Because our first priority is the safety of the public and our
residents, we have taken the following actions,” Lanterra wrote in a statement
issued to the press. “Lanterra Developments has … stipulated that the
tempered glass on these balconies will be replaced with a laminated glass…”
That’s three properties worth of glass balcony retrofits, with the decision
made even before the engineering firm brought in to investigate the breakages
could determine the problem.
In its statement, Lanterra noted: “The advantage of utilizing laminated
glass is that in combination with using the latest available railing technologies,
these laminated panels retain their structure in the event of a fracture
and stay in place on the balcony should any breakage occur … Effective
immediately all of our projects in development will make similar use of
laminated glass designs.”
However, as one glass supplier commented to USGlass on the condition that
they remain unidentified for fear of losing customers: “They are still
dodging the key issues of the tempered failures. Was it heat soak-specified
or not? Was it heat soak delivered or not? [In other words], was it a
developer/architect failure or a supplier failure?”
As the consumer press has begun to report additional breakages—causing
several developers to replace tempered lites with laminated glass in an
effort to curb further negative publicity—the answer to that question
has become increasingly more important to the North American glass industry.
Searching the Specs
Three of Lanterra’s properties have been affected by glass breakages,
according to local news reports. One Bedford at Bloor, a 32-story tower
in Toronto designed by KPMB Architects, was completed in 2009. KPMB’s
website notes that the north tower features projecting sandblasted glass
horizontal balconies. KPMB also designed the TIFF Bell Lightbox, which
has reported glass breakage from its condominium tower this summer as
Lanterra’s Murano condominium has towers located on 37 Grosvenor St. and
38 Grenville St., both of which were completed in 2009. The two-tower,
glass-encased condo was designed by architectsAlliance. The complex was
named after the island of Murano, in reference to the artwork on the podium
curtainwall that portrays the glass artistry of that island.
Toro Aluminum Railings, an 11-year-old manufacturer of balcony guard railings,
has handled the glass replacements for Lanterra. The company fabricated
and installed the balcony on the Murano’s south tower, while another now
out-of-business company handled the other towers’ balconies (Lanterra
would not provide the name of that company). According to a statement
Toro issued on August 19, the railing manufacturer “supports the installation
of heat-treated laminated glass balcony railings.” According to the technical
data listed in its website, the company mandates for its railings: “All
glass to be 6 mm (1/4-inch) tempered in compliance with CAN/CGSB-12.1-M90.”
However, representatives of Toro Aluminum would not return USGlass’ requests
for comment as to whether it has promoted heat-treating tempered glass
in the past. And neither Toro, Lanterra nor the architects involved on
these projects would answer the most asked question: who supplied the
"The only reason there
is a perception that tempered glass is getting a bad name is because
the [consumer] press covering the current Toronto story have yet
to draw the distinction between domestically produced tempered
glass, and those products that come from China … "
Pulp Studio Inc.
“It’s a sticky situation,” says one glass supplier who asked
not to be named in connection with this article. “The developer and the
contractors are in damage control. The developer is trying to avoid the
perception that this is only a symptom of other shoddy construction practices
and that other parts of the building(s) are sub-standard.”
Without answers from the parties involved, the glass industry has drawn
its own conclusions.
Follow the QR code to view this USGlass archived article on managing the
problems inherent in tempered glass.
The Toronto developer gained a publicity reprieve of sorts on September
1 when, for the third time, a glass balcony at the Four Seasons Hotel and
Private Residences in Seattle shattered.
According to local news reports, that property is following the suit of
other developers and removing the tempered glass from every balcony.
Neither the Four Seasons management nor the general contractor on the project,
Lease Crutcher Lewis, would respond to USGlass’ requests for comment. However,
in October 2008, a year before this hotel-condominium was completed, Business
Excellence published profile of the general contractor, which referenced
the Four Seasons Hotel. The profile offers insight into the contractor’s
approach to materials: “Materials such as casework and curtain wall [sic]
can be procured from China at 20-30 percent below what’s locally available,”
it says. The article goes on to quote the company’s Jeff Cleator: “When
the owner applies for construction financing, he wants to eliminate budget
uncertainty, so we’ve gotten more creative with purchasing. In some cases
we will purchase and store materials ourselves and then assign those contracts
to the appropriate subcontractors after the traditional bidding period.”
It’s a perspective that has left many North American glass suppliers nodding
“The only reason there is a perception that tempered glass is getting a
bad name is because the [consumer] press covering the current Toronto [and
Seattle] story have yet to draw the distinction between domestically produced
tempered glass, and those products that come from China (assuming this material
came from there),” says Bernard Lax, chief executive officer of Pulp Studio
Inc. in Los Angeles, who has no knowledge of the suppliers involved.
Many domestic suppliers are drawing that same conclusion.
A Critical Distinction
It’s a distinction that glass and railing suppliers unconnected with these
specific projects are urging their customers to recognize.
“I believe there is a lot more scrutiny and consistency with ingredients
that go into making glass by North American float glass manufacturers, so
I feel far more comfortable with glass produced domestically,” says Bob
Lawrence, president of Craftsman Fabricated Glass in Houston.
That’s one point on which most North American railing suppliers seem to
“Make sure that your glass is coming from a source that can be trusted,”
emphasizes Brant List, a sales consultant for Q-Railing USA.
“It’s all about the glass. It’s all about knowing your supplier and knowing
what’s in your glass,” added another railing fabricator who asked not to
be named for this article for fear of losing customers.
“[It] does have a lot to do with glass sourcing,” agrees Tony Leto, executive
vice president of sales and marketing for The Wagner Companies in Butler,
Wis. “Most domestic manufacturers of glass have become pretty good at making
sure that their glass doesn’t have the nickel sulfide inclusions [impurities
in glass that can cause spontaneous breakage], but if people are using imported
glass, they have to be a little bit more aware and insist on that heat soaking
to make sure there’s no imperfections in there.”
Andrew Chatfield, director of architectural glass systems for The Wagner
Companies, points out that “there are regulations and standards for break
testing on glass. If you talk to anybody who tempers glass, they will tell
you that every so often they have to run a sample through and they have
to break it and there’s a set criteria for how that glass breaks, how many
pieces per square inch of fractured pieces of glass there are.” He notes
that customers need to be educated to ask for testing and certifications.
When the suppliers in these cases become public, perhaps these comments
will change. But perhaps not. As Lax points out, glass breakages are not
new. They’re just heavily reported at this time, possibly causing more consumers
to view the material with a nervous eye.
“Chinese tempered glass has had numerous project failures around the country,
and not just in exterior glass,” Lax says. “I can only assume that many
of these are related to nickel sulfide inclusions. It took our domestic
industry decades to remove this element from their production facilities
and I image it will take decades before the Chinese industry can insure
the same. In the meantime, if I were a building owner I would require all
the glass I purchased from China be heat soaked in the United States to
insure the quality before installing it.”
The Laminated Solution
Both the Toronto developer and the Four Seasons have remained mum on the
glass supplier. But, when it comes to the tempered versus laminated railing
debate, does it matter?
“Given recent publicity I have recently been recommending that laminated
heat-strengthened glass be offered as the smart alternative for the [railing]
applications,” Lawrence says.
“Is replacing everything with laminated the right answer?” asks the unidentified
glass supplier quoted earlier. He answers that question with another question:
“Why is the developer running away from tempered, which is common enough
and works well when it’s specified and fabricated well? Perhaps they are
avoiding tempered to pin the blame on tempered, rather than on their sourcing
Rob Botman, general manager of Glassopolis in Toronto (unconnected to the
projects mentioned), offers an alternative view, one that isn’t looking
down where the glass is falling—after all, the point of using tempered glass
in these applications is that if it does break it’s not in large shards
that will cause serious injury—but up at the balconies where this glass
is meant to protect building occupants.
“Remember that tempered glass is designed for safety, not strength,” Botman
says. “It passes impact-safety tests if the glass pebbles when it’s broken.
Laminated, on the other hand, passes the same tests if it keeps the broken
glass in place. As a parent with small kids, if I was living in a condo
with a glass balcony 40 stories up, I’d prefer laminated over tempered.
What’s more important when my kids crash into that balcony glass: keeping
my kids on the balcony or making sure the pieces of broken tempered glass
pebbled up safely when they fall to their deaths?”
For his part, Botman says, “I’d like to see more laminated balcony glass.”
Still, others point out that tempered glass is typically specified in these
applications over laminated glass for one reason: cost.
“It’s obviously a cost issue,” Leto says. “One of the things that often
is said is, ‘well, it met code.’ People have to realize that the building
codes are considered minimum standards for safety. As minimum standards,
that means you always can do better. And in certain situations, the minimum
standards are not [enough]; when you’re dealing with a safety issue in a
high-rise you may want to exceed the minimum standard and go with something
that’s less likely to fail.”
While that one railing fabricator earlier emphasized “it’s all about the
glass,” that too is a point of contention. Some say it’s all about the installation.
more important when my kids crash into that balcony glass: keeping
my kids on the balcony or making sure the pieces of broken tempered
glass pebbled up safely when they fall to their deaths?"
–Rob Botman, Glassopolis
In fact, that same unidentified fabricator who points out “it’s all about
the glass,” says that company does its own installation to ensure that
its products meet code requirements.
Others say it’s not all about the glass; it’s about how the metal touches
“The thing you have to be aware of is the edge contact,” Leto says. He
theorizes that this may have played a role in another much-reported case
of glass railing breakages.
For the W Austin Hotel in Austin, the problems began on the pool deck.
On June 10, two lites of glass fell from the balconies of south-facing
condos on floors 24 and 25, crashing down and injuring four people on
the pool deck below.
Weeks later, three more lites fell.
Following the latter incident, which caused minimal damage to cars but,
fortunately, no injuries, the property owners issued a statement saying
“that one glass panel on the 31st floor was broken and that the resulting
falling debris broke panels on the 29th and 22nd floors.”
According to the financial statement filed by hotel owner Stratus Properties
Inc., the breakage caused the hotel to close for 11 days while it investigated
the problem. Even before the investigation conducted by Curtain Wall Design
& Consulting (CDC) in Dallas was complete, the property owners made
the “decision to replace every balcony glass panel on the building” with
In its September online survey, USGlass asked readers to select the solution
they feel is the best way to prevent glass railing breakage. The results
are pictured here. To take next month’s survey, visit www.usglassmag.com
From the Report
The W Austin Hotel, which opened December 2010, was designed by Andersson-Wise
Architects. Featuring highly reflective windows, a press release on the
architect’s website notes that the tower’s primary facades are oriented
north-south, with differing apertures composed to control daylight, heat
gain and energy use. It adds that the south façade features “generous,
A June 11 CDC preliminary investigation report shows an etched label on
one glass panel had the name of China’s Xinyi Glass (XYG). The company
has North American operations in Richmond, B.C. The logo notes that the
glass was safety tempered in compliance with ANSI Z97 and CPSC 16 CFR.
Representatives at XYG declined to comment.
U.S. Railing in Tampa, Fla., a subsidiary of Custom Components, served
as the balcony railing system designer, fabricator and installer on the
project. The company directed media inquiries to Stratus, which released
a statement from chief executive officer Beau Armstrong.
“A thorough investigation of this incident continues with numerous engineers
and experts to ensure this work is done as safely as possible,” Armstrong
CDC’s report on the initial incident stated: “In an effort to locate the
initial source of possible falling debris, we have confirmed that a pattern
of damage does exist emanating partially from the slab edge at level 27
directly above the failed units. Based on our initial observation of this
area, it appears that high strength grout applied to the slab edge has
been dislodged adjacent to a post tension cable head location. The high
strength grout appears to have fallen onto the top edge of the glass unit
at level 25. Cementicious debris collected on levels 25, 24 and the pool
deck is consistent with the missing grout on level 27.”
In its conclusions and recommendations, CDC’s report said, “due to the
location of the point-supported glass in-fill panels any falling debris
could likely damage the top edge of glass, causing catastrophic failure.”
As Leto says, “I think people need to be reminded that glass edges are
extremely susceptible to damage from impact.”
This case certainly provides a vivid reminder. Leto continues, “We’re
very big on pushing the idea of having a top rail on glass if that’s the
glass balustrade railing. Now, that might have simply been an in-fill
panel with an exposed edge, but exposed edges are very susceptible to
breakage, even under minor contact.”
It’s a caution that may come too late, as frameless railings that allow
for an unobstructed view only continue to grow in popularity.
“A lot of people are going for the ¾-inch glass without a cap rail,
so they don’t have anything obstructing their view; it’s just a glass
panel,” List says. He continues, “A lot of people are telling me, ‘well
we’re going to use ½-inch and we don’t want to use a cap rail.’”
List notes that building codes differ by locality, but, “the rule of thumb
is anything over ¾-inch glass with soft edges does not require
a cap rail.”
“We are seeing a greater demand for glass railings in general, mainly
because of this desire in residential as well as commercial to have this
unrestricted view. So there’s a lot of push to include glass wherever
they can so they can have an invisible railing,” Leto agrees. “Our warning
as always, though, is that there are a lot of misconceptions that you
can do that without a top rail, and doing without a top rail is very risky
for many reasons.”
Watching the Edge
But there are other delicate points of contact that can lead to spontaneous
breakage such as seen at the W Austin.
“They were dealing with a building that was southern exposure in Austin,
Texas, in the summer. So more than likely everything expanded and eventually,
as the glass edges hit some metal somewhere, it would have just exploded,”
He continues, “You have to be aware of where the edges of that glass are
going to possibly contact metals. There are a couple of places where that
could have happened: the holes through the glass where the clips attach,
if that material moved and there wasn’t a proper buffer in there, it could
have broken. Or if the outside edges of the glass expanded enough to hit
a post or other solid contact, that could have caused fracturing.”
It’s an installation factor that is occasionally overlooked, Chatfield
“If you’re drilling a hole through the glass then you want to make sure
that obviously … the metal screw or whatever is going through the hole
is isolated from the inside edge of the hole. A lot of people tend to
forget that little piece of plastic grommet that goes in the hole, and
wonder what that is and throw it away. Then of course as all the glass
expands, there’s differential expansion between the metal and the glass,”
He adds, “Everyone knows the building site is never exactly correctly
to drawing as far as dimensions are concerned. Tolerances are unbelievably
important and the consideration of tolerances when you actually fabricate
something is important. We realize it with railings, the way we do things,
because we now have products that allow for thermal expansion, mechanical
movement within the system. That’s unbelievably important, because obviously
metal moves, and if it’s on the south face it’s going to move a lot more
than it’s going to move if it’s on the north face or on the east face.”
During the summer, as consumer newspapers reported on glass falling from
the skies, glass suppliers and railing manufacturers looked on nervously.
But with the negative publicity comes an opportunity for the glass industry
to educate designers and developers that they don’t have to give up those
sweeping views—but they have to embrace those glass railings wisely.
As Chatfield points out, “There seems to be more instances [of breakages]
in Canada and I think that’s probably because they’ve had an explosion
in condo construction certainly in the Toronto vicinity.”
“It is not uncommon for a builder and developer to hire an architect for
his expertise and then ignore his advice and conventional wisdom in an
effort to save money. Now that the truth comes out they have to spend
a lot more to fix a problem they helped create,” Lax adds. “Developers
who buy exterior glass from offshore and do nothing to test and guarantee
its quality should all be shaking in their boots … They should always
remember it was the low bid that built the Titanic and be proactive about
the money they spend when it comes to issues of public safety.”
Being able to lay these instances before designers, and explain the importance
of using a knowledgeable supplier and certified products to prevent problems,
could help savvy railing and glass suppliers.
Chatfield, who hails from the United Kingdom, says that glass use is embraced
more slowly in the United States than in Europe. “I think we’re moving
faster now, but certainly where we use glass in the building is still
far removed from where we use it in Europe,” he says. “I think some of
it has to do with logistics in the United States but also it’s a matter
of people feeling comfortable with using the material.”
Obviously, increasing the use of glass in a multitude of applications
is the industry’s collective goal, and educating specifiers on glass’
safety properties may help in realizing that goal.
“That’s what makes these recent cases critical,” Leto adds, “because that
only breeds the fear that glass isn’t an appropriate option. It’s not
that it isn’t an appropriate option; you just have to take proper precautions
and engineer properly to make it work.”
Megan Headley is the editor of USGlass. She can be
reached at firstname.lastname@example.org
or follow her on Twitter @USGlass.
Follow the QR code to view this USGlass archived article on managing the
problems inherent in tempered glass.
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No reproduction of any type without expressed written permission.