We use cookies on this site to enhance your user experience. By clicking "I AGREE" below, you are giving your consent for us to set cookies. Privacy Policy

text.skipToContent text.skipToNavigation

Innovative Solutions for Curtain-Wall Framing

Technical & Installation Notes

Simpson Strong‑Tie has developed a line of connectors for use with curtain-wall steel stud framing. Curtain-wall projects require a variety of connectors that provide a load path from the curtain wall to the primary structure for wind loads, seismic loads and dead loads. Slide-clip connectors enable the structural building frame to deflect independently of the curtain-wall system. Fixed-clip connectors support the dead load of a curtain wall from the structural frame. Fixed clips have the added benefit of providing connector solutions for load-bearing walls and for roof systems utilizing steel trusses and rafters.

Our connectors for curtain-wall construction accommodate many different bypass framing applications in a variety of stand-off conditions. We also offer connectors for head-of wall and strut applications.

Tailored To Your Design

Our standard slide clips accommodate either 3/4" or 1" of both upward and downward movement, equivalent to an L/360 live-load deflection for a 30' span. Our standard clips also accommodate stand-offs as large as 25". For deflections greater than 1", or job-specific conditions, Simpson Strong‑Tie can provide custom clips to suit most framing needs.

Complete, Tested Solutions

Designers of curtain walls will often know the capacity of a connector, but since the capacity does not take into account the way in which the connector is anchored to the supporting structure, the designer must then manually calculate this important aspect of the connection design. These calculations are complicated by considerations of eccentric and prying forces that often exist but are difficult to predict. Through comprehensive testing Simpson Strong‑Tie provides total, code-listed connector solutions. Our testing extends from the capacity of the connector and its attachment to the framing, to the anchorage of the connector to the primary structure. By providing complete data on the entire connection system, we save the designer time and ensure that all forces, including eccentric and prying forces, are adequately considered.

As with all Simpson Strong‑Tie products, our slide-clip and fixed-clip connectors for curtain-wall steel stud framing carry our promise of quality and performance, and are backed by prompt, knowledgeable service.

Curtain Wall Framing Section

General Information and Notes for Curtain-Wall Framing Connectors

Slide-clip and fixed-clip curtain-wall framing connectors represent key components that comprise a continuous load path between curtain-wall steel-stud framing and primary building structure.

In light-frame cold-formed steel construction, primary building structures typically consist of structural steel or structural concrete base material. Hence, connectors for curtain-wall framing are designed to anchor to steel or concrete to resist tension and compression load, perpendicular to wall, due to wind pressure, shear load due to gravity weight of the CFS framing, and in-plane load, parallel to wall due to earthquake or high wind force.

General Notes

  1. Allowable loads are for use when utilizing the traditional Allowable Stress Design methodology. Contact Simpson Strong-Tie for LRFD loads unless otherwise noted.
  2. Allowable loads may not be increased for wind or earthquake load.
    Allowable loads are based on cold-formed steel members with a minimum yield strength, Fy, of 33 ksi and tensile strength, Fu, of 45 ksi for 43 mils (18 ga.) and thinner, and a minimum yield strength of 50 ksi and tensile strength of 65 ksi for 54 mils (16 ga.) and thicker. (U.O.N.)
  3. Clips do not replace lateral or stability bracing. Design of bracing is the responsibility of the designer.
  4. It is the responsibility of the Designer to veriFy the adequacy of the stud. Allowable loads are based on clips installed an adequate distance away from penetrations, notches, ends of studs and other conditions that may affect the clip performance.
  5. It is the responsibility of the designer to check the adequacy of the supporting structure for loads imposed by connectors.
  6. Industry studies show that hardened fasteners can experience performance problems in wet or corrosive environments. Accordingly, use these products in dry and non-corrosive environments only.

Anchorage to Structural Steel

Anchor to structural steel using self-drilling screws, powder-actuated fasteners, or welding are based on installation in a minimum 3/16" thick structural steel with Fy = 36 ksi. (U.O.N.)

  1. Allowable loads for #12–24 self-drilling screws are based on a minimum nominal shear strength, Pss, of 2,520 lb. and nominal tension strength, Pts, of 2,535 lb. It is the responsible of the designer to select the proper length fasteners based on installation need. Screw length must ensure fastener extends through the connection a minimum of three exposed threads.
  2. Allowable loads for Simpson Strong-Tie PDPAT-62KP powder-actuated "tophat" fasteners also apply to alternate fasteners with a minimum shank 0.157", a minimum head diameter of 0.300", a minimum allowable shear of 410 lb. and tension strength of 260 lb. for A36 steel, and a minimum allowable shear of 420 lb. and tension strength of 305 lb. for A572 or A992 steel per ESR-2138. "Tophat" fasteners are recommended to ensure adequate clamping force and consistent installations.
  3. Allowable loads for welded connections require E70XX electrodes with a minimum throat size equal to the clip thickness. Welding shall be in compliance with AWS D1.3. Welding galvanized steel may produce harmful fumes; follow proper welding procedures and precautions.

Anchorage to Structural Concrete

Anchor to concrete or masonry such as Titen® 2 screws, Titen HD® screw anchor, Strong-Bolt® 2, or various type of epoxy for post installed are based on installation in concrete with a minimum f'c = 2,500 psi and a maximum f'c = 4,000 psi. Reference the current Anchoring and Fastening Systems for Concrete and Masonry catalog for more information.

  1. Allowable loads for Simpson Strong-Tie Titen 2 concrete and masonry screws also apply to alternate fasteners with a 1/4" diameter with hex head style, a minimum allowable shear of 300 lb. and tension strength of 415 lb. for concrete minimum f'c of 2,500. Titen 2 screws install easily in a predrilled hole and include a drill bit in each box.
  2. Titen HD is a heavy-duty screw anchor for use in cracked and uncracked concrete as well as uncracked masonry. Titen HD is available in 1/4", 3⁄8" and 1/2" diameter for anchorage used in curtain-wall framing connector.
  3. Strong-Bolt 2 is a wedge-type expansion anchor designed for optimal performance in cracked and uncracked concrete as well as uncracked masonry. Strong-Bolt 2 is available in 1/4", 3⁄8" and 1/2" diameter for anchorage.