The Protective Glazing Council (PGC) Spring Meeting wrapped up yesterday at
the Embassy Suites Busch Gardens in Tampa, Fla.
Wednesday afternoon wrapped up with a panel discussion moderated by Joseph
Smith of Applied Research Associates tackling issues ranging from windstorm/hurricane
code compliance and blast hazard mitigation to forced entry protection and personal
safety enhancements, such as "safe rooms." The panel consisted of Valerie
Block of DuPont Building Innovations; Code consultant Charlie Everly; Nanette
Lockwood with Solutia; and Doug Hall of Applied Research Associates. Each member
of the panel gave a short presentation on selected topics before opening the floor
to questions from the audience and general discussion. Topics from the question
and answer session ranged from using multiple technologies to secure a building,
to designing for hurricanes and blast mitigation, to how to keep specs straight
when working with architects or others who may change them mid-project or having
someone who wasn't involved in the planning process writing the specs.
Kicking off St. Patrick's Day, Block returned to speak about how ASTM E1300-04
can be used to determine the load resistance of glass in buildings-and how it
can't.
"It's a tool you can use to come to some decisions on proper thickness
to use on some types of glass," she said.
A quick survey of the audience showed that about half of those present used
the standard. Block explained the changes the standard has undergone in recent
years, as well as how those changes may impact its use, including the change in
load duration from 60 seconds to three seconds in the newest version.
"This is important because we always ask 'are we talking about a three-second
gust or a 60-second duration?' I can't make this point more strongly. Even though
the standard now says three second loads, that doesn't mean everyone knows it.
It's worth your while to make sure you're using the duration that the code you're
using requires. You have to compare apples to apples for proper duration,"
Block said.
Following Block, Peter Vickery with Applied Research Associates spoke on the
topic of hurricane loss reduction through window protection (also the title of
his presentation).
"I'm here to talk about not code compliance but non-code compliance that
will help, such as window film and tempered glass," he said. He then launched
into an explanation of the software used to simulate hurricane winds on different
structures, as well as the data used and the results of many an animation of a
windstorm's effects on an ill-built house.
Vickery also demonstrated some real-world testing, launching shingles (weighing
between .9 lbs to 5.4 lbs), clay roof tiles and 2-by-4s at various speeds and
pressures at windows to see how they would react. The windows were either annealed
or tempered, some with daylight applied film, others without any protection. All
of the windows were put through a cycling test.
"We were very surprised with the pressures we got to with window film,"
Vickery said. "Remember, these are daylight applications. Film will do a
lot better with attachments. You also get a lot of protection out of tempered
glass."
Vickery said his preliminary conclusions are that the current pressure cycling
standards are "too severe," that window film "provides effective
means of eliminating damage associated with window breakage for most small missiles
and is more effective if attached," and that more testing is needed.
Though held in Florida and heavy on hurricane damage prevention measures-for
obvious reasons-the PGC spring meeting did also cover blast mitigation. Darrell
Barker of ABS Consulting, who took to the podium after Vickery, discussed the
topic and how and when to introduce aspects of blast mitigation into the building
equation. He also touched on why it's better to have all the details in place
before work begins, including the criteria the customer wants.
"You'd think this would be a big issue, but we see them sometimes with
blanks still needing to be filled in. If it's not done at the beginning, it will
create problems down the line," Barker said.
Other details included threats and hazards to be mitigated, the level of protection,
whether testing will be required and, tying it all together, the budget.
"Understanding what's in the budget right down to the systems [is important].
Don't let a project proceed with an undefined budget," he said. "Decisions
are made on things other than the lowest cost."
Wrapping up the conference was Marc Percher with Hinman Consulting Engineers,
the company conducting the study of emergency ingress/egress through fenestration
with protective glazing. An update of the presentation made by Holly Stone at
the fall meeting last September, Percher said the company has conducted additional
testing, developed a preliminary rating system for windows and expects to publish
a report in the near future.
The next PGC meeting is scheduled for November 9-10 in Washington, D.C. Check
the PGC website (www.protectiveglazing.org)
for more information as it becomes available.