Volume 43, Issue 7 - July 2008

Bring in the Subs

New ASTM Language Makes Hurricane Product Substitution Easier and Less Costly by Ellen Rogers

The market for hurricane-impact glazing products is growing fast. In fact, forecasters predict that by 2012 it will be a $380 million industry—not surprising considering how building code changes have continued to mandate the use of these products. 

In order to keep up with the demands, manufacturers developed products for hurricane-prone regions. But what if, in an effort to expand their offerings, a manufacturer wants to make a slight component substitution to the system? Before even thinking about a substitution, manufacturers must send their products through rigorous rounds of testing in order to prove compliance with ASTM. Until recently, one little change would require the product to again go through the same testing procedures—and that can get expensive. But now, thanks to a new ASTM annex, manufacturers may just find simple substitutions to be a lot easier and a lot less costly.

Refresher Course
As hurricane protection in building codes has increased, so, too, have the number of curtainwall and window system manufacturers testing their products in accordance with the designated standards and procedures. Both Florida’s Product Approvals and Miami-Dade County’s Notice of Acceptance (NOA) require that products pass the Testing Application Standards (TAS) as specified in the Florida Building Code (FBC). The International Building Code (IBC) specifies that products must pass ASTM E 1996 Standard Specification for Performance of Exterior Windows, Curtain Walls, Doors and Impact Protective Systems Impacted by Windborne Debris in Hurricanes.

The TAS and ASTM test requirements are similar, though the pass-fail criteria are somewhat different, with the FBC being more stringent. Both call for impact, cycling and air, water and structural testing, with three identical units required to pass impact and cycling tests, and one unit passing the test for air, water and structural performance. ASTM allows for a 5-inch tear in the interlayer material through which a 3-inch sphere could pass; Miami-Dade allows only a 5-inch tear that’s no wider than 1⁄16-inch. Likewise, ASTM allows for missile penetration through the specimen, while Miami-Dade does not.

But testing requirements are not the only differences. Dade County also allows for product substitutions within the systems. For years certain allowances have been permitted so that a manufacturer could test and qualify a variety of glazing and frame options within a single series of tests. Sounds great, right? And it is great—so long as you are testing for that specific code requirement. What about the other jurisdictions in hurricane-prone regions? Many enforce versions of the IBC, which has referenced ASTM E 1996 for hurricane protection since 2000. Unlike Dade County, ASTM E 1996 made no allowances for substitution, and manufacturers soon began requesting it. 

“ASTM needed to be updated and comparable to Miami-Dade because not everyone follows that protocol,” says Julie Schimmelpenningh, architectural technical application manager for Saflex, a unit of Solutia Inc., and recording secretary for ASTM E 06, the committee responsible for ASTM E 1996. Now, thanks to the efforts of an ASTM working group, an annex is now available within ASTM E 1996-08 that will help manufacturers when it comes to product substitutions. 
Prepare Now: NOAA Announces Predictions for 2008 Atlantic Hurricane Season
Glass businesses located in hurricane-prone regions are preparing for what the National Oceanic and Atmospheric Administration (NOAA) is predicting to be a “near normal or above normal” Atlantic hurricane season.

“Living in a coastal state means having a plan for each and every hurricane season. Review or complete emergency plans now, before a storm threatens,” says retired Navy Vice Admiral Conrad C. Lautenbacher, Ph.D., undersecretary of commerce for oceans and atmosphere and NOAA administrator. 

According to the NOAA’s Climate Prediction Center, this year’s Atlantic-basin hurricane season can expect “considerable activity” with a 65-percent probability of an above normal season and a 25-percent probability of a near-normal season.

Just what can we expect from a “normal” or “near normal” season? Predictions say we have a 60- to 70-percent chance of 12 to 16 named storms (sustained winds of at least 39 miles per hour), including six to nine hurricanes (winds reaching 74 miles per hour) and two to five major hurricanes (winds reaching 111 miles per hour). Many glass businesses in hurricane-prone states still have fresh memories of life after a massively destructive storm. They are now using those lessons learned as they ready themselves for whatever this season may bring.

Jack Raleigh, owner of National Top & Glass in Fort Lauderdale, says doing business after a hurricane is extremely hectic and one way to be prepared is to have enough supplies on hand in advance.

“Suppliers often don’t have enough product and you end up having to drive all around looking for what you need,” Raleigh says. He also says working with the insurance companies can also be a challenge.

“After Hurricane Andrew [the insurance companies] said to just fix everything, but after the last one we had they are becoming more worried about the price,” says Raleigh, who explains there have been times where he had to pay more for the glass than the insurance companies wanted to pay.

And what about preparing his business for whatever this year’s season may bring and the long work days that will follow?

“I’m going to make sure I’m prepared by having all my generators ready,” says Raleigh. 

General Rules for Substitution
General premises for substitution require that three out of four initial specimens have passed all the appropriate criteria in ASTM E 1996 and the original specimens are identical in every way, including anchorage and mounting. The general premises that apply to any substitution are:
• A larger size qualifies smaller as long as dimensions do not exceed the dimensions of tested width or height; 
• Small missile: all elements that are not infill elements shall be allowed automatically;
• Automatically substituted elements can be combined into a system without requiring engineering analysis or testing;
• Components equal to or stronger than the components originally tested [can be substituted];
• Substitutions are allowed when the design pressure is equal to that which the three initial specimens were qualified;
• Substitution is not allowed if a failure occurs for any reason;
• No more than three substituted elements can be combined before retesting is required;
• Glazing tapes, sealants, adhesives and backbedding substitution requires a single test; and
• Glazed products must be impacted twice per unit (even if initial panels only had one impact per unit).
Rules for Interlayers
• Any substitution of interlayer manufacturer or type requires testing one additional specimen that is identical to the initial three qualified with the only change being the interlayer type or brand;
• A decrease in interlayer thickness by more than 10 percent for the same type interlayer as was originally qualified is not allowed;
• A decrease in interlayer thickness up to 10 percent for the same type or brand as was originally qualified requires one test;• Increasing the thickness of an interlayer from the same manufacturer and type as was originally qualified is automatically accepted;
• Changing the color of the interlayer that is of the same manufacturer and type as was originally qualified is automatically accepted; and
• Interlayer decorative treatment of the same manufacturer and type as was originally qualified is automatically accepted, provided the decorative treatment does not contact the glass or plastic glazing (i.e., located between two layers of interlayer).
Rules for Glass Infill Panels
• Color change is an automatic substitution; no additional testing is necessary;
• Substitution of a glass coating (reflective, coated, low-E, frit, etc.) is automatic once it is determined that the product is durable and compatible with all the components of the system;
• An increase in individual glass ply thickness requires that one additional specimen be tested. A substitution where the glass ply thickness is decreased is not allowed;
• Changing the glass type from annealed to heat-strengthened or chemically strengthened requires one additional test specimen;
• Changing the glass type from heat-strengthened to annealed or heat strengthened to chemically strengthened is not allowed;
• Changing the glass type “to” or “from” fully tempered is not allowed; and
• Decorative surface (sandblasted, acid-etched, etc.) substitution is not allowed.
Rules for Insulating Glass Units
• Glazing detail shall be unchanged other than to accommodate a thicker unit;
• Monolithic or laminated lites must be attached to the glazing leg or bed in the same manner and position as originally tested;
• Systems with a glazing stop or bead require a single test;
• Systems without a glazing stop or bead are automatic;
• Changing from a system approved with an insulating glass unit to a monolithic or single laminated unit is not allowed; and
• Asymmetrical insulating glass unit orientation (order of lites from outboard to inboard) cannot be altered from the way it was tested originally. 
Source: The information above was interpreted from ASTM E 1996-08 and printed in the Saflex Spring 2008 newsletter.


Ground Work

Three years ago a working group consisting of industry manufacturers, consultants and test lab representatives was formed to develop substitution language for an annex to ASTM E 1996. 

David Hattis, president of Building Technology Inc., served as the chair of the ASTM task group that developed the annex.

“It’s [the annex] important because the impact test for fenestration is a performance test based on three identical specimens submitted to a rigorous testing regimen,” says Hattis. “Questions had come up in regard to manufacturers that make a slight change to the system that would not affect the product’s performance. Since testing is required of three specimens, would that mean if a [slight] change were made that three more specimens had to be tested?” Hattis continues, “We wondered whether it would be possible to categorize the changes into groups so that in some cases changes could be made automatically without re-testing; some changes would require testing.”

Luke Turner, code compliance engineer for PGT Industries and a member of the working group that developed the annex, says the new language will be helpful for manufacturers in that it will reduce the testing required.

Substitution Language
That language was completed this past April and is now available as part of ASTM E 1996-08. Though the original specification contained basic language on the idea, it was very minimal.

According to the new language, general premises for substitutions require that three out of four initial specimens pass all ASTM E 1996 criteria and that original specimens are identical in every way (see boxes on page 38 for more information). There are then three categories by which a substitution could be made:

1. An automatic
substitution requires no additional testing;
2. Engineering analysis requires that performance be demonstrated or documented through a review of materials that predicates a minimum of equivalent performance; and
3. Single specimen, which requires that a specimen identical to the original be qualified with the only difference being the component that will be substituted (such as the interlayer type). 

For example, simply changing the color of the glass is an automatic substitution, but increasing the thickness of the glass would require one additional test. Decreasing the thicknesses of the glass would not be allowed. 

Manufacturer Matters
As a manufacturer, Turner says his company is often faced with a need to make a component substitution, so the new language will be helpful.

“We want to be able to sell different product options within the same product line,” Turners says. “Before this new language, as part of the ASTM specification we’d have to limit our product offerings because there was no substitution testing. Now, we can offer broader product offerings and it’s less costly because there’s not as much we have to test.” 

Turner explains that each test can cost thousands of dollars. “So anything to cut down on that is helpful.”

Hattis agrees that the new language will be beneficial for manufacturers.

“They will see less confusion on the extent of testing a whole window line that has different alternatives,” says Hattis, “so it will be simpler for those manufacturers that have a line of related products.”

Dan Luna, an architectural consultant with Arch Aluminum & Glass in Tamarac, Fla., says that most major manufacturers of hurricane systems are already complying with Miami-Dade. He explains that after Hurricane Andrew Miami-Dade County, with the State of Florida close behind, developed its own code. All the major fenestration products manufacturers had to get their products approved.

Soon after, Miami-Dade County and Florida created a website where all of their approved products could be listed to show the details of their NOA. 

“To me, this database was truly one of the most useful tools that was ever published on the web, as well as a great marketing tool,” says Luna. “I am sure this provided added incentive to manufacturers to get their products approved.” 

Now, with the majority of fenestration manufacturers already meeting the more stringent testing requirements—which allowed for substitutions—the new ASTM language may not be significant for everyone.

“Some manufacturers in states that require wind-borne debris protection have chosen to test their products per the ASTM standards,” says Luna. “These companies will reap the most benefit out of the changes made in the ASTM standards. It seems strange that the more stringent code allowed changes and product substitutions more easily than its perceived easier counterpart, but [it will be helpful] that they are again aligning themselves.”

Still, when it comes to meeting the ASTM requirements the biggest benefit will be the minimal costs of testing and the ability to offer more options.

“Manufacturers are able to sell a greater diversity of products and only test the core elements that matter to the product’s performance,” says Schimmelpenningh. “It gives them the ability to change out what doesn’t affect the performance.” 

USG
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