From Glass Magazine, June 2003
WHAT'S NEXT?
Keeping up with fire-rated glass and framing

By Jerry Razwick

For fire-rated and security glass and framing, the past few years have brought tremendous change - in products, codes and in the way people think about the role of glass in fire protection.

The change has not been limited to new product introductions. For example, one of the most recent changes centers around the oldest fire-rated glazing material on the market: wired glass. In just the past few months, new guidelines have been established that dramatically affect the way wired glass will be used in the future.

In 2002, the newly formed International Code Council (ICC) determined that all fire-rated glazing in grammar schools, high schools and athletic facilities must meet the U.S. Consumer Product Safety Commission impact safety standard.

This change is having a widespread effect on school districts nationwide, because wired glass has been a nearly universal building material in educational facilities. Decisions are being made not only concerning new construction, but how to handle replacement glass as well.

Glaziers have many alternatives. Many of the fire-rated glazing products filling the void significantly outperform wired glass on several levels. With no wires and longer lists of features, the newer products are opening design possibilities that were never an option until now.

One immediately noticeable difference is the size of fire-rated opening that can now be achieved. Some of the new fire-rated ceramics can have an exposed area per piece of up to 23 square feet, as opposed to 9 square feet for wired glass. And when you include the product category know as "glass walls", that number jumps to nearly 40 square feet per piece. The result is fewer mullions, greater visibility and improved aesthetics.

As might be expected, current choices on the market have addressed the impact safety issue that wired glass could not. There are a number of products that fully comply with CPSC 16CFR1201 (Category II), providing at least four times the impact resistance of wired glass. They meet the highest safety impact requirements and are excellent options for locations that will see high volumes of foot traffic.

Building construction is still in the wake of 9/11. New safety and security measures are being implemented across the board. The public is demanding that extra precautions be taken to plan for every possible contingency.

Glazing has been no exception. In some instances, fire-rated applications need bullet resistance as well. The problem is that most bullet resistant glass is also highly flammable, due to its make-up (that commonly uses plastics). As with the wired glass situation, people have been left to make a hard decision about which to make the priority -- fire or bullet resistance.

Not anymore. Today, architects can specify a 2-hour fire-rated glass wall product that has also earned a Level III bullet resistance rating (indicating it can stop a .44 magnum bullet). Like other bullet resistant glass, the fire-rated glass wall is made up of multiple layers of glass. But the special interlayer enable it to provide outstanding fire resistance that the other bullet resistant products can't match.

This trend toward products that serve multiple needs seems to be growing. It is somewhat mind-boggling to see a clear piece of glass that can do so many different things. In addition to impact and bullet resistance, fire-rated glazing materials can now also offer energy efficiency, security ratings, acoustic control and a wide range of aesthetic options. Fire-rated glass that is also hurricane and blast resistant may be the next frontier.
Advances in framing

While the changes in fire-rated glazing stretch back over the past two decades, it has only been within the past few years that there has been significant movement on the framing side of the equation. Until fairly recently, North American framing options for fire-rated glass were by and large limited to hollow metal steel and L-angle brackets.

It was only a matter of time, however, until the inventiveness characterizing fire-rated glazing spilled over into framing. The same needs for performance and appearance options propelled framing in new directions.

One of the first major shifts came with the introduction of narrow profile steel framing. With ratings from 20 minutes to 2 hours, the framing looks and installs much like ordinary aluminum storefront, yet with the exceptional strength of steel. The slim construction gave designers a completely new alternative to the wrap-around bulkiness of hollow metal steel. The narrow profile framing has now also been tested in stainless steel, which expands the aesthetic options even further.

Sometimes steel of any kind is just not appropriate for a particular application. Many buildings are better suited to wood framing. Since wood is combustible, however, the concept of fire-rated wood framing has seemed unattainable. However, in a remarkable achievement, new hardwood framing has been able to earn a 45-minute fire rating. The frames have an engineered core with a thick hardwood face. Some of the frames feature throated construction and are installed prior to drywall, substantially reducing installation and finish carpentry time.

Another "unthinkable" that is now becoming a reality is fire-rated curtainwall. For interior atriums and building exteriors close to property lines, fire protection is frequently a real concern. The new fire-rated steel curtainwall framing with ratings up to 2 hours provides a means for incorporating large expanses of glass. Using a pressure glazed system, the curtainwall is available with a variety of custom face caps (including stainless steel) to match the overall project.
The challenge of change

Unquestionably, all the new product development is proving to be a boon to design. It is always preferable to have several options from which to choose.

But the variety can prove challenging as well. Ratings and performance characteristics can differ greatly from product to product, requiring some careful research before making any selection.

The process can be simplified by following a few key steps. First, check to ensure that the rating of the product matches the required rating for the opening. Make sure the product has an unqualified listing for the size needed.

It is also helpful to talk with someone inside the industry. There may be new glass and framing options that you have not yet heard about, and a quick phone call to a fire-rated glazing professional can bring you up to speed.

Finally, be very cautious when it comes to making substitutions for a specified fire-rated product. Many times, an architect may have design reasons for specifying a particular product. While alternate glass and framing materials may meet the required performance criteria, and may be lower cost, they may not meet the required aesthetic needs. In that case, the products are not "equal", and may be rejected prior to or after installation.

Innovations and advances in fire-rated glass and framing will only increase as codes tighten and market needs grow. Products will continue to raise the bar for safety, performance and appearance. And that makes for a very bright future.

©2003 Technical Glass Products