by Thom Zaremba, shareholder at Roetzel & Andress
In my last blog, we found out that some fire-rated glass in the windows, doors and walls of our buildings is quietly standing guard, ready to protect us from the deadly smoke, flames and hot gases of fires. In today’s blog, we’re going to peek behind the curtain to see if we can find out where this fire-protective and fire-resistant glass may be hiding in plain sight.
In Recognition
However, before beginning our search, I’m going to start today’s blog with a special salute to all the tremendous people who work in our industry, the best industry in the world, the glass industry!
Who are they?
They start with all the geologists who scour the earth every day to find the perfect sand and other raw materials needed to make glass. They also include all those working in float plants that use high heat to change those raw materials into glass, one of the most important building and container materials the world has ever known.
It also includes the men and women that research the extraordinary science of glass—how to make it break safely; how to make it so thin it can be used in your phone; how to add coatings to make it energy efficient or transfer electric current to its edges in photovoltaic installations; and, perhaps most importantly, how to use it to keep us safe from fires, hurricanes and even bullets. It also includes all those who form glass into bottles and drinking glasses, and all those who fabricate glass into doors, windows and walls, and install them into homes and businesses all over the world.
To all those working in the glass industry, I SALUTE YOU!
Quietly Standing Guard
Now back to the search. Where is fire-protection- and fire-resistant-rated glass hiding in our buildings?
Let’s take a walk.
As we approach an apartment building, it’s obviously built close to several other buildings. If a fire were to break out in any of them, it might spread to the others. Does that mean the glass in the curtainwall, the glass in the vestibule, doors and windows on the exterior walls of these buildings is fire-protection- or fire-resistance-rated glass?
Yes, it does!
Building fires not only move up and down inside a building, but a fire in one building can quickly spread to other nearby buildings.
Perhaps the most famous fast-spreading fire was the Great Chicago Fire of 1871. There, 300 people died when fire spread from one building to another until some 17,000 structures across more than three square miles were on fire. That catastrophe left no doubt that buildings constructed near each other need to use fire-rated glass and other fire-rated construction materials capable of stopping the spread of fire from one building to the others built around it.
Now, let’s go inside the building and take the elevator up a few floors. Exiting the elevator into a corridor, there are apartments on both sides. At both ends, “exit” signs are visible. Walking down the corridor toward one of the exit signs, each apartment door has glass in it, a glass sidelight next to it and glass in a transom above it. Is all this glass fire-rated?
To answer that question, we need to know that in commercial buildings, including apartment buildings, the word “exit” has a special meaning. It means a building’s “exit” consists of three parts:
- The exit access;
- The exit; and
- The exit discharge.
The signs pointing us to exits at the ends of the corridor indicate that we are in the exit access of this building. That, in turn, will lead us to an exit that takes us directly to its exit discharge. In the event of a fire, when you’re at the exit discharge, you should be safely outside the building. Why? All parts of the exit must protect occupants fleeing a fire using passive, fire-rated construction materials.
Returning to our original question, yes, all the glass in that exit access corridor must be fire-protection- or fire-resistance-rated. It will likely look like the glass in any other window or door, but because it is fire-rated, it will be silently standing guard, waiting to protect people while they leave their apartments and head to exits in the event of fire.
In my next blog, we’ll look at why active and passive fire protection are needed to keep building occupants safe in today’s age of electronics. Stay tuned!