Volume 35, Number 4, April 2000

 

Generating Explosively Hot Ideas in

Fire-Rated Glazing

Contract Glaziers Working Closely with Architects to Offer Design Solutions
are Invaluable Members of the Design Team

by Nils Brinkmann

How times have changed.

Today, carmakers rush to introduce the newest safety technology. Side-impact air bags, anti-lock brakes and five-star crash-test ratings are considered entry-level requirements for new cars to be marketable. What was once a burden has become an integral component in basic automobile design.

Not unlike the automotive industry, when codes first began requiring fire-rated glazing in commercial buildings, many architects viewed the new standards as restrictive, limiting their aesthetic options to wired glass.

Today, in addition to wired glass, a flood of clear fire resistant and fire protective glasses have entered the market, making it possible for designers to create virtually any look they desire. In fact, many of the new products offer so many distinctive features that it is conceivable for architects to specify them where they might not have originally envisioned glass at all.

Of course, this rapid expansion of the industry has made specifying fire-rated glass much more complex. Architects are often unaware of the vast choices. Contract glaziers are in the unique position of being able to offer outstanding design solutions that may never have occurred to the specifier.

 wpe1C.jpg (43932 bytes)New fire-rated framing options offer narrower profiles for more design flexibility.

Clearing the Way

One of the most recognizable changes in fire-rated glazing has been the arrival of non-wired products. Historically, wired glass has been the backbone of the industry, and to this day, polished wired glass sales account for the majority of fire-rated glazing.

On some occasions, however, the wired look may not be the first preference. Although wired glass is tough in a fire, it may not be particularly suited for those locations where the clear look of natural lighting and aesthetic appeal, or where impact safety is an important issue.

 

Top of the Line

In many cases, wireless glass products bring with them higher performance capabilities. It isn’t unusual to find glazing in places that at one time were off limits—simply because there wasn’t a product that could meet the need.

For example, in Florida, officials saw a number of injuries related to their three-hour fire-rated warehouse doors. Since the doors were solid, people passing through couldn’t see what (or who) was on the other side of the door. There was also concern that firefighters would not be able to assess a situation because there was no visibility through the door.

The solution came in the form of a newer, clear and wireless fire-rated glass ceramic with a fire rating of up to three hours. Though not a barrier to heat, code officials have approved the use of the product in vision lites for three-hour doors.

However, the clear products have really made a design difference in replacing wired glass, as a substitution for entire barrier walls. Most would picture something as imposing as a brick wall when they need a two-hour rating, but new transparent wall units literally open up the possibilities for entirely different design approaches.

Multi-layer intumescent products and gel-filled glass units perform as transparent wall systems, which means these products not only stop the spread of flames and smoke, but also block heat transfer. These products remain clear, giving sharp vision until exposed to fire. When the interlayers foam up, they turn into insulating, opaque heat shields that block out the fire and give a positive signal that the fire is close by.

 

Sizing Up the Situation

wpe1B.jpg (62429 bytes)
Function and form meet in today’s fire-rated doors and windows. Architects can now satisfy code requirements and safety concerns without compromising aesthetics.

If you know your building codes from years gone by, you may recall that the standard limitation on fire-rated glass used to be 1,296 square inches. Since that was the largest size at which wired glass could pass the testing requirements, it was the maximum allowable size per piece. Now that virtually all the fire-rated glass products on the market today can greatly exceed 1,296 square inches and still survive the tests for fire ratings, current codes now allow products to be used as large as tested successfully. Even wired glass, when glazed with a specific sealant and framing, has listings for much larger sizes. The obvious benefit is that architects are free to specify larger pieces of glass, and more of it.

 

Crossing the Line

One particularly dynamic aspect of the new era in fire-rated glass is that many of the products perform multiple functions. Few products on the market today are strictly “fire-rated” – most offer additional features that make them even more attractive.

While fire safety is important, the glass may have additional roles to play. One vital function that often overlaps with fire protection is impact protection. It is far more likely that a sidelite will face fast moving objects than it will a fast moving fire. That’s why many fire-rated glass products also offer a level of impact safety performance. Generally, this isn’t nominal impact protection; a number of the glazing materials can meet CPSC 16 CFR 1201 (Cat. II), the highest level of impact safety offered in glass.

 

Topping of the Edges

Fire-rated glass predominantly is required in interiors, but there are cases where the code calls for a fire-rated exterior product. In these cases, an insulating glass unit (IGU) can be installed with fire-rated glass ceramic or multi-layer heat barrier glass on one side and a float glass product on the other. Such IGUs can also be used as acoustic or security barriers, or to offer one-way viewing.

Getting Narrow-Minded

One component of the fire-rated glazing system that has been fairly static is the framing. Typically, hollow metal steel is the primary option, with the exception of some custom framing for individual types of glass.

For several years now, European codes have allowed the use of sleeker, slimmer, profiled steel framing and doors with fire-rated glass. Having been tested to North American standards, such framing is beginning to enter the United States. Users now have the option of narrower profile framing for both the standard fire-rated glass products and the barrier-to-heat transparent wall units.

Such advancements will expand the design possibilities far beyond what has previously been allowed. Entire walls of glass can now be specified, with greater exposed areas and less intrusive framing.

 

Then and Now

With all the changes in fire-rated glazing, there is a critical need for contract glaziers to be fully in touch with the latest developments in the industry. Architects also need to be fully aware of their capabilities and/or limitations of the new option. For example, one product on the market today carries severe restrictions and conditions on its 60-minute listing, conditions that are easily overlooked if no one reads the fine print. Rather than simply quoting whatever products are specified, glass professionals can provide the much needed service of investigating products thoroughly, making sure they are suitable for a given application. At times, it may be possible to suggest an alternative that would be equally appropriate aesthetically but far less of a liability risk. Architects rely on glaziers as the “glass experts.” If you are able to protect them (and yourself) from potential lawsuits, you have the opportunity to greatly strengthen your relationship with them as a vendor.

So how can you possibly keep track of this rapidly growing field? By following some simple steps:

1. Check out all specified
products.
Research the listings of the products you’re asked to quote, particularly if you see something new or if “limitations” are mentioned on the label. Do they carry the required fire-ratings and/or impact safety ratings for the job? Don’t rely strictly on the manufacturer’s literature; independent laboratories such as UL and Warnock Hersey provide unbiased information about exactly what each product can and cannot do.

2. Develop relationships with sources in the industry. Finding a good, reliable source of information at a manufacturer or distributor level can give you the inside track to what’s going on in fire-rated glazing. If you have a particular project in mind with a need you’re not sure how to meet, chances are you’ll save a great deal of time with a simple fact-finding phone call.

3. Take up surfing. A great deal of valuable information is available over the Internet. You can now quote fire-rated glass via the web. And often, electronic information is updated more regularly than printed material, making the facts more current.

With fire-rated glazing headed in new and exciting directions, the potential is unlimited. Glaziers who take advantage of the opportunity can ride the wave of innovation to new levels of profitability and success.

Nils Brinkman has served as sales manager for fire protecting glasses at Pilkington Flachglas AG in Gelsenkirchen, Germany for the past three years. Most recently, he has been appointed the new general manager for USA Pilkington Pyrostop.


USG

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