WHAT IS FIRE-RATED GLASS?
To be approved as fire-rated glass, a number of conditions must be met. The Building Code generally specifies the types of fire tests that a fire-rated glass must pass. Manufacturers submit their products to a testing lab, like UL, for testing to these standards. If the glass passes, the testing body, such as UL, publishes the results which say what glass was used, and how big the glass was that passed, and any other conditions that may be required (e.g. the use of a particular glazing compund or tape). Manufacturers must thereafter ensure that any glass sold for installation as a fire-rated glass must be no bigger than what passed the tests and is labelled by the fabricator to indicate that this is the case. Fire-rated glass is not generally sold in sheet or by the case, but instead is sold in cut-to-size pieces that are officially labelled under contract to a testing body, like UL, as passing the required tests. In other words, its Glassopolis’ job to ensure that you always get only fire-rated glass that is fully tested to North American standards and is properly labelled and ready for inspection by the building code official after installation. We will not sell anything that is not approved. Period.
WHAT IS CLEAR FIRE-RATED GLASS-CERAMIC?
Fire-rated glass-ceramic is a special formulation of glass engineered to be insensitive to high temperatures. It doesn’t expand or contract with changes in temperature, unlike regular annealed glass which therefore immediately cracks when heated non-uniformly. Glass-ceramic survives the high temperatures of fires and helps keep smoke and flame from travelling through a building. This makes glass-ceramic ideal for fire separations in buildings, and is in fact the only monolithic glazing that meets the requirements of the International Building Code in key glazing applications.
What is PYRAN®?
SCHOTT PYRAN® is the best glass-ceramic on the market and the preferred choice of industry professionals. Other more expensive brands exist, but only because some sales rep seduced an architect into specifying it. When professional glass contractors have a say, they pick SCHOTT PYRAN®.
SCHOTT PYRAN® glass-ceramics come in a range of grades and configurations, so you can get exactly what you need. The SCHOTT PYRAN® line includes the highest quality glass on the market and also the most affordable glass-ceramic. Don’t settle for somebody else’s yellow/brown glass when you can have colorless SCHOTT PYRAN® in your project.
WHEN SHOULD I USE WIRED GLASS?
The short answer is: you should never use traditional regular wired glass again. It breaks too easily and dangerously. Instead, try new Protect3™ Safety Glass from Glassopolis or upgrade further to glass-ceramic.
Until the development of glass-ceramics, like SCHOTT PYRAN®, traditional wired glass was the best thing around. In a fire, traditional wired glass breaks immediately but is more or less held together by the wires, providing some sort of barrier to flame and smoke, but not much. Traditional wired glass is very dangerous in impact safety applications. The wires actually weaken the glass’ strength and act like fish hooks if someone accidentally crashes through the glass. When broken and breached, the razor-sharpness of the wire combines with jagged glass edges, greatly increasing the severity of impact injuries. There have been numerous injuries and lawsuits involving wired glass. Eventually, the 2006 International Building Code finally removed traditional wired glass as an option for fire-rated applications. In short, don’t use it.
Instead offer your customers the clear alternative to traditional wired glass: SCHOTT PYRAN® glass-ceramics which make your windows look like clear windows again. Hundreds of jurisdictions have already undertaken complete retrofits of their schools and other public and private buildings, removing their wired glass, and replacing it with safety-rated PYRAN® products.
For applications where cost is a key issue and the look of traditional wired-glass is accptable, try Protect3™ Safety Glass from Glassopolis. It is wire glass that has been modified and specially laminated with only fire-rated materials to be much safer than traditional wired glass. It passes both stringent impact-safety tests and fire-rating tests to provide a safe, affordable solution that complies with the revised building codes. Each piece of Protect3™ Safety Glass from Glassopolis comes properly labeled for use and meets both ANSI 97.1 and CPSC 16 CFR1201 Category II impact-safety requirements, making it a safe, affordable and building code compliant choice for many applications. See Protect3™ Safety Glass CPSC 16 CFR 1201 impact-safety information.
BOTTOM LINE: The use of traditional wired glass in impact safety applications should be completely eliminated. Fire-rated glass-ceramics, particularly with safety film or laminated, are a much safer and vastly better looking alternative. The economical Protect3™ Safety Glass is now available as a safe and code compliant option as well.
HOW IS FIRE-RATED GLASS INSTALLED?
It is very important that Fire-rated products are installed according to their installation detail and are otherwise in full accordance with the conditions they were tested under. Framing materials, stop heights, glazing compounds and tapes can all be specified by the glass manufacturer as being required. Each product is slightly different, so Glassopolis works for you to make sure you get those details right, every time.
Installation into framing: Fire-rated glazing must be installed into fire-rated framing OR into a wall interface detail that maintains the inherent fire-resistance of the wall itself. In all cases, the glass must meet or exceed the rating of the framing or wall construction to result in an assembly featuring the same rating. Essentially, the lower figure is the governing figure. As one example, if fire-rated glazing is installed into an aluminium frame, the overall rating of the assembly is strictly governed by the rating of the aluminium frame, given that aluminium generally is un-rated. As a second example: if 60-minuted rated glass is installed into 120-minute rated framing, the rating of the overall assembly is the lesser rating, which is 60 minutes.
Installation into drywall openings: Ceramic glass can be installed into correctly-designed, borrowed lite openings in drywall. You will require simple 3/4" steel L-angles, PYRAN® glass, fire-rated drywall, correct setting blocks and glazing tape, a few other common components, and a bit of skill. The key factor is that the lesser of the two major components (the ceramic glass OR the wall/drywall system) dictates the fire-rating of the overall glazed opening. As always, work within the maximum glass sizes for the required fire rating. Please call Glassopolis or visit www.GLASSOPOLIS.com for our related Technical Bulletins.