Galvaspan ™

Galvanized Steel Curatin Wall Back Pans


Galvaspan™ galvanized steel back pans are installed on the interior face of curtain wall systems in spandrel areas and are secured to the wall framing using appropriate fasteners. The cavity of the back pan is filled with mineral wool or fiberglass that is pin welded to the steel pan. Sealing of back pans to mullions is the glazier’s responsibility.

Galvaspan™ galvanized steel back pans are available in 20 or 22 gauge galvanized steel, and 4 profiles to suit a variety of conditions. All brake formed back pan corner joints and seams are spot welded, then sealed using a butyl rubber, component sealing compound. The interior side of the pans may be painted as an option for aesthetic reasons i.e. where back pans are visible from the building interior. Painted back pans typically have the insulation secured using self-stick pins.


In curtain wall construction the control of heat flow is generally achieved through the use of insulation. Although it is not apparent from the exterior, the curtain wall system uses considerable insulation usually behind spandrel glass or any opaque panels. Because of the materials used in the structure, i.e., glass and metal, which are highly conductive, the system must also contend with potential condensation on the interior surfaces. To curtail this effect, most curtain wall systems incorporate three distinct features: a sealed double glazed window or an insulated metal pan, a thermally broken mullion, and a rainscreen design.

For Optimum Energy Conservation and Interior Appearance


1. On interior face of the curtain wall system in the spandrel area or behind opaque panels.
2. New or retrofit construction.
3. Over steel, concrete, masonry or wood structures.
4. Concealed, or exposed locations (painted backs).

Dimensional Criteria

Galvaspan™ back pans custom fabricated to suit project requirements.
Pan Depth: Fabricated up to 125 mm (5″) thickness in any increment.
Gauges: 20 and 22 gauge are standard however pans can be fabricated in any gauge to suit designer’s requirements.
Over Size Pans: Back pan sizes greater than 2.3 m² (25 square feet) are custom fabricated with an integrated joint stiffening design.


The profile of Galvaspan™ back pans is dependent upon the sequence of building component installation, how the glass is installed, whether new or retrofit work, and other variables. SpandrelTech Ltd. can advise construction professionals on design.

Custom Profiles: Other back pan profiles or shapes can be fabricated. Contact SpandrelTech Ltd. for requirements.

Structured Incremental Shipping

If required, we will coordinate manufacturing and shipping panels on a floor-by-floor or elevation-by-elevation basis for installation convenience.

Options & Finishes

Paint Finish (Optional): If Galvaspan™ back pans are exposed to the interior of the building, the exposed side of the back pan may be painted to meet customer requirements.

Design Considerations

Air leakage increases energy costs and reduces occupant comfort in both the winter and summer. The air barrier system used to control air leakage in a curtain wall is usually comprised of glass, metal framing, metal back pans, and the seals that connect all of these components. Care is required in detailing and construction to ensure that the plane of air tightness is continuous. To guarantee performance in a curtain wall system, designers should specify a maximum allowable air leakage rate and the relevant test standard. The Architectural Aluminum Manufacturers Association (AAMA) can provide guidance in this regard.

Specifiation (Short Form)

Spec Note: See long form 3-Part specification at end of “Galvaspan™ Galvanized Steel Curtain Wall Back Pans” section of manual.

Curtain wall back pans: “Galvaspan” custom fabricated [20] [22] gauge steel pans [galvanized] [and] [painted___colour], sizes as shown on the drawings as manufactured by SpandrelTech Ltd., 16 Erin Park Drive, Erin, Ontario N0B 1T0; Tel: (519) 833-9684 or 1-888-833-9684; Fax: (519) 833-0845; Email:;