Back with Another Innovative UL System for Back Pan Curtain Walls!

Jun 19, 2019 by James P. Stahl, CFPS, Vice President & General Manager, Engineering and Emerging Businesses

We are pleased to announce the very first UL System for a back pan curtain wall system where the vision glass sill is flush with top of floor and the back pan does not have a stiffener channel. Our new UL System, CW-D-1044, represents the latest curtain wall perimeter fire barrier system to supplement the industry’s most complete package for edge of slab firestopping.

The system provides a 2 hour F Rating for a variety of different spandrel types, including glass, aluminum, stone, and aluminum composites. It features both aluminum and steel anchors. The steel back pan is exposed on the interior side and insulated with mineral wool curtain wall insulation. The safing system consists of 4 pcf (64 kg/m3) mineral wool safing insulation installed to a 4” (102 mm) depth with SpecSeal® Safing Spray, Fast Tack®, or AS200 Elastomeric Spray. An optional shadow box may also be incorporated.

But it does not stop there. No, this system includes two other features that are also industry firsts!
• The glass and aluminum panels may be secured with structural silicone glazing!
• The curtain wall insulation may incorporate a vertical seam!

It is worth noting that the sill position in this design is important. If the sill should be anything more than flush, it would require the use of a different design (i.e. one that will incorporate integral steel stiffeners in the back pan or a supplemental insulation shelf below the safing system.

When is a stiffener or safing shelf appropriate?
In the case of CW-D-1044, the sill proximity to the floor line helps. When the sill height is not flush, it would be appropriate to reference a design such as CW-S-0002 or CW-D-1033, which will incorporate steel stiffeners and a safing shelf to help mitigate the effects of deflection on the steel back pan. STI has the right systems for all your perimeter fire barrier needs!

Download PDF of Article Here