Before considering TYCO Model WS and FireLite Plus WS as alternate products for 1-2 hour walls, it is important to consider the hidden risks and costs of these alternates compared to already approved, readily available and USA-made 1-2 hour fire resistive glazing assemblies.
The bulletins below are resources to help architects and authorities having jurisdiction (AHJs) understand the safety trade-offs, design restrictions and additional upfront and ongoing maintenance costs when specifying or approving TYCO Model WS and FireLite Plus WS as alternate products.
What are the IBC requirements for 1-2 hour walls?
Glazing that meets the ASTM E-119 standard are classified as “fire resistive” or “fire-resistance-rated” in Chapter 7 of the IBC. Marked with a “W”, it can be used as fire barriers in exit enclosures, exit passageways or horizontal exits to ensure that building occupants are protected from smoke, flames and dangerous radiant heat as they exit a burning building.
Given this important life safety function, the ASTM E-119 test is the most stringent and most difficult test to pass for all fire rated glazing assemblies – and rightfully so. The test specimen has to withstand temperatures of over 1800 degrees F without the passage of flame or gases hot enough to ignite cotton waste for the entire duration of the test; has to pass prescribed hose stream test; and has to limit the temperature rise on the non-fire side to less than 250 degrees F over ambient.
Are the TYCO Model WS and FireLite Plus WS products tested to ASTM E-119?
Due to extensive code lobbying, a modified, less stringent version of the ASTM E-119 test now applies to special-purpose sprinklers used with fixed glazed assemblies (such as TYCO Model WS and FireLite Plus WS) as an alternative product requiring prior AHJ approval for 1-2 hour fire resistive wall assemblies.
Other than following the time and temperature curve, there is nothing that resembles the original ASTM E-119 test. There is no cotton waste test, there is no hose stream test, and there is no documented report showing how it limits the temperature rise on the non-fire side to less than 250 degrees F over ambient.
What happens to the assembly when the sprinklers fail to work?
When the sprinklers fail to operate, the non-rated glass will be useless in preventing fire, smoke and dangerous radiant heat. Building occupants are no longer protected, and safe egress becomes almost impossible.
Wetting the surface of heat-strengthened glass or tempered glass may prevent thermal shock and compartmentalize smoke and flames, but it won’t prevent the passage of radiant heat.
Ceramics may be able to resist cracking or shattering at high temperatures because it is an excellent conductor of heat. This is why it is widely used as cooktops, and why the IBC limits its use to fire protective applications only because it does not limit radiant heat whatsoever.
Are the TYCO Model WS and FireLite Plus WS alternates more affordable compared to 1-2 hour fire resistive glazing?
Not really. If you factor in all the costs for submitting the required documentation for AHJ approval (including hydraulic calculations per installation), additional water supply for the special-purpose sprinklers (must have the capability of supplying 1 or 2 hours of water, depending on the rating of the wall), upfront material and installation costs for the special-purpose sprinkler system (includes sprinkler heads, pipes and other plumbing), additional cost when using expensive laminate ceramic for FireLite Plus WS and the ongoing maintenance of the special-purpose sprinkler system throughout the life of the building — it becomes more expensive.
1-2 hour fire resistive glazing do not need prior AHJ approval, it does not rely on sprinklers and there are no maintenance costs after it is installed. USA-made fire resistive glazing costs up to 50% less than laminated ceramic at for 1 hour walls and up to 20% less for 2 hour walls.
If you are looking for a readily available, USA-made, code-approved, tested, listed and labeled fire resistive glazing products that do not require prior AHJ approval, contact your local SAFTI FIRST architectural representative today or call us toll-free at 888.653.3333.