CONTINUES TO ADVANCE
As Government Projects Keep
Contractors Busy, More Glass Companies Enter the Protective Glazing Fray
By Megan Headley
In the ten years since September 11, 2001, citizens of and
visitors to the United States have grown accustomed to a world of heightened
security. By 2003, when Sandia National Laboratory released the report
Assessment, Development and Testing of Glass for Blast Environments, the
glass industry knew that protective glazing could play an important role
in protecting building occupants from all manner of threats.
The report stated: “Evidence that hardened windows can protect personnel
is provided by the performance of the new windows in the renovated section
of the Pentagon when it was struck by an airplane on September 11, 2001.
Recently completed retrofits to the structure included installing thermally
tempered and laminated windows designed for blast-resistance. Many of
these windows did not fail even when they were exposed to the aircraft
fuel fireball, thereby preventing fire from entering many of the offices
around the crash location.”
From there, the demand for protective glazing products grew. Just as importantly,
the demand has remained relatively steady in the last two years as government
funding has kept afloat the construction schedules of federal buildings,
military bases and other government projects while commercial and residential
construction waned. As a result, protective glazing products have moved
from a highly specialized niche to a demand everyone in the glass industry
is looking to supply.
Everybody’s Doing It
No doubt about it, protective glazing is a hot spot right now.
“In the last ten years I’d say the biggest change in protective glazing
and custom applications of it have become the majority of the work that
we do,” says Gantt Miller, chief executive officer of Winco Window in
As more manufacturers begin producing these products, glazing contractors
are lining up to put them in.
Stewart P. Jeske, P.E., president of JEI Structural in Kansas City, Mo.,
agrees. “There are a lot more contractors that are trying to enter into
this area because that’s where a lot of the money is right now,” he says.
Today, the nation’s largest real estate developer, the General Services
Administration (GSA), is putting more construction companies, and their
glazing subcontractors, to work on projects requiring a level of security.
“Most of the projects have been courthouses, airports and every new or
retrograded government installation,” says Ricardo Carrillo, principal
consultant with Acumen Industries in Conroe, Texas.
It’s not just the U.S. government, points out Vic Cornellier, president
of TSI Exterior Wall Systems in Landover, Md. “It’s every government,
so embassies, consulate offices, private developers even that might have
a building full of defense contractors. If government representatives
are going to be in those buildings, then they have to have a blast regulation
also,” he says.
As demand grows, so too do the number of contractors and fabricators working
with these materials.
Breaking Out of the Mold
Cornellier recalls installing blast jobs 15 years ago, when Norshield
in Montgomery, Ala., was about the only supplier of those products.
Back then, Cornellier recalls, “Each government agency was developing
its own criteria and they weren’t communicating, like [they had] trade
secrets. Then GSA … standardized blast performance. But there are still
agencies that work independent of that.”
Greg Galloway, product marketing manager for YKK Architectural Products
in Austell, Ga., explains that today, “There are two main organizations
that provide standards and job specifications. GSA manages more than 9,000
government buildings and uses GSA TS01-2003 [GSA-TS01-2003 is the test
standard used by GSA and other agencies using the Interagency Security
Committee’s (ISC) Security Design Criteria]. The Department of Defense
(DOD) promulgated the United Facilities Criteria (see “Future Changes
Coming to UFC, ASTM F2248 Standard” in the box below). It is a prescriptive
standard built specifically around the use of polyvinyl butyral (PVB)
as the interlayer.” He notes, “DOD administers requirements for military
bases and they tend to rely more heavily on controlled perimeters: fences
and people with guns at checkpoints.”
These regulations, Cornellier says, formed the start of the blast industry.
With standards in place, new companies began to enter the fray. “Usually
the commodity [suppliers], have products that meet the low level of blast,
so at least they’ve got their foot into the door.”
Coming to UFC
by Matt Quinlivan
For the past several years, the Unified Facilities Criteria (UFC
4-010-01) has been the governing code for all U.S. Department
of Defense (DOD) blast mitigation projects. Referencing ASTM F2248-03,
Standard Practice For Specifying An Equivalent 3-Second Duration
Design Loading For Blast Resistant Glazing Fabricated With Laminated
Glass, the UFC provides a guideline for determining an appropriate
static design blast pressure for both framing and connections
of blast-resistant glazing systems.
Surprisingly, many engineers and glazing contractors are unaware
of the requirements set forth by ASTM F2248-03 for the design
of framing connections for blast-resistant glazing systems. ASTM
F2248-03 specifies connection design loads of at least 2.0 times
the magnitude of the 3-second equivalent design load or the glazing
resistance as determined from ASTM E1300, Standard Practice For
Determining Load Resistance Of Glass In Buildings, whichever is
greater. Often the glazing system connections to the main structure
are only designed to resist 2.0 times the 3-second equivalent
design load, despite the glazing resistance of the system.
The UFC 4-010-01 currently is undergoing revisions that should
clarify blast design loads and reference a more stringent version
of the ASTM F2248 standard—ASTM F2248-09. ASTM F2248-09 sets forth
the following criteria for the design of blast-resistant framing
connections to the main structure:
a. 2.0 times the magnitude of the load resistance of the blast-resistant
glazing if the maximum air blast pressure is greater than one
half the magnitude of the load resistance of the blast-resistant
b. 1.0 times the magnitude of the load resistance of the blast-resistant
glazing if the maximum air blast pressure is less than one half
the magnitude of the load resistance of the blast-resistant glazing.
Currently, UFC 4-010-01 (the 2007 revision) references ASTM F2248-03,
and not the more up-to-date F2248-09 edition. It is our understanding
that ASTM F2248-09 is not required in the design of blast-resistant
systems until referenced in the most current version of the UFC,
which is anticipated before the end of this year.
The changes may be difficult to accommodate with static equivalent
analysis and may require a larger push for dynamic blast analysis
to maintain reasonable connections.
Matt Quinlivan, E.I.T., is an
with JEI Structural Engineering. This article is reprinted courtesy
of JEI Structural Engineering.
“Ten years ago it was a lot more cookie cutter,” Miller agrees. Today,
suppliers looking to stand out may move to more custom systems.
But challenges, of course, face glass fabricators and especially installers
jumping into this specialized arena.
“A lot of time the glazing contractors are not very informed on these
[protective glazing] issues, and so when-
ever they bid these [projects] they may not know what to look for in the
specifications,” Jeske says. “They end up getting burned on the back end.”
For example, Jeske sees, “they’re supposed to submit calculations on down
the road and, a lot of times, they haven’t been thoroughly educated in
the specs what to look for … Or they don’t understand that it requires
three times the amount of anchors that they were originally thinking about,
or that the system that was originally tested under blast loads does not
really meet the requirements that were specified. So they get into a lot
of messes that way.”
Cornellier has worked on enough projects with blast requirements to know
that they take a lot more time, a lot more money and a lot more experience
than non-blast projects.
Walking through the process, he explains, “You end up having to design
to calculations based upon requirements that are set forth in the specifications.
Then the owners, be it the government or individual companies, hire a
blast consultant. They give you design criteria and then you have to submit
calculations that show that you’re meeting that design criteria.” From
there, “All the data is interpreted: you have to understand what the intent
of the design is, then you have to interpret it, then you submit your
interpretation, and they tell you whether you got it right or you got
Cornellier says he sees as much as 75-percent additional time spent on
engineering and submittals for these projects compared to non-blast.
Carrillo agrees that the calculations required often pose a problem—but
in a different way. He recalls bidding a government project where the
specification required a specific tool for analyzing the effects of blast/dynamic
forces upon glazing. “It utilized information other than the traditional
equivalent static forces methods employed by most consulting engineering
firms to design safety and blast resistance glazing.” Problem was, he
found, access wasn’t granted “unless you were already a government-approved
As the market segment grows, more resources are becoming available to
help glazing contractors and their
customers (see below).
In 2010, the Glass Association of North America and Protective Glazing Council
International published a joint Protective Glazing Manual, which incorporates
a history of the protective glazing products including films, interlayers
and glass. The manual goes into depth to describe typical applications (ballistics,
blast, hurricane/seismic, security, etc.) and pertinent information on testing
standards and building codes. Both organizations have published documents
for download on their websites, www.glasswebsite.com
Valerie Block, senior marketing specialist with DuPont Glass Laminating
Solutions based in Wilmington, Del., notes that while building codes have
not adopted security glazing requirements that address terrorism, an increasing
number of architects on government and many high profile commercial projects
are including blast requirements in their architectural specifications.
“This has prompted manufacturers to test and market blast-resistant doors,
windows, storefront and curtainwall systems that incorporate laminated
glass,” Block says. “Last year we sponsored several rounds of shock tube
and arena testing to evaluate glazing systems made with PVB and ionoplast
interlayers. Both interlayers are effective in reducing flying glass fragments,
a potential cause of injury after a blast event.”
Julia Schimmelpenningh, global applications manager of architectural,
advanced interlayers for Solutia Inc. in Springfield, Mass., has likewise
seen interest in protective interlayers.
“With the terrorist attacks there was a huge interest peak in the desire
for bomb blast protection,” Schimmelpenningh says. “Many door and window
companies restructured or adapted their framing systems to handle the
common loads that would be placed on them based on the typical blast loads
being used. This represented a large amount of interest in laminated glass
and the awareness that common ¼-inch laminated glass with 0.030-inch
or greater interlayer thickness offered a tremendous level of protection.”
In recent years, Galloway has found that designers specifying blast performance
are looking for increasingly stronger levels of protection.
“[We] do an increasing number of blast projects,” he says. “Until the
last couple of years, most projects specified a 3b level of performance
[ISC’s “high” protection level; see “ISC Security Criteria Glazing Performance
Conditions” - see below]. That is, after the blast test, fragments of
glass are allowed up to 10 feet away from the test specimen. This can
be achieved with PVB as the interlayer.”
Today, Galloway says, “We are seeing an increasing number of specifications
asking for a level 2 [ISC’s “very high” protection level].”
As with the protective products being sold in hurricane zones (see July
2011 USGlass, page 22), designers of government buildings are looking
for more than protection from attack. They’re looking for a work environment
with natural light and that also performs efficiently.
“Since 9/11, the glass and protective window/protective fenestration industry
have significantly advanced the quality and performance of extreme load
and ballistic-resistant products. Key to this has been the development
of protective product systems that also provide energy efficiency in architecturally
acceptable packages,” says Joseph L. Smith, PSP, principal engineer, director
and senior vice president of Applied Research Associates, an engineering
and research company in Albuquerque. “Physical testing, coupled with more
advanced high fidelity analytic modeling, has allowed for the
use of lighter, more efficient and cost-effective design solutions.”
Schimmelpenningh agrees that when safety glazing is needed, architects,
designers and building owners are now looking for bundled performance
options, “meaning safety and security as well as energy and sound control,”
she says. “As the awareness has grown over the decade, the products have
evolved with options to meet most needs. It’s the willingness to incorporate
these options at the build, making them part of the initial performance
requirements and building use concepts, that have changed most,” she adds.
However, performance can lead to challenges for fabricators.
Companies entering this evolving market segment are sure to find additional
challenges of their own.
Megan Headley is the editor of USGlass
© Copyright 2011 Key Communications Inc. All rights reserved.
No reproduction of any type without expressed written permission.