Other specific mandatory requirements in this section deal with the following.
System scope
To include elements that comprise the specified system and related work to be performed, including any or all of the metal framing, anchoring devices, glazing, roofing elements, siding panels, or operable building windows.
Fasteners
Fasteners should be of sufficient hardness, yield, and tensile strength to bear the weight of the wall, withstand imposed dynamic forces, and also must accommodate the fabrication and construction tolerances and thermal movement.
Protective coating for metals
The guide specification lists third-party standards and specifications (federal, ASTM, AAMA) that should be referenced for finishes or integral coatings on steel or aluminum.
Frame design to enable glazing from exterior or interior
This is the architect’s choice, but glazing from the interior is preferred.
Sealing and glazing materials
Sealing must accommodate thermal movement, inter-story differential movement, concrete creep, column foreshortening, and seismic movement.
Fabrication
Referenced to drawings and bills of material, properly finished welding (per American Welding Society [AWS] guidelines), alignment, and fit evaluation criteria.
Metal work joints
Requiring careful matching of assembled components to provide continuity of line and design with accurately fitted and rigidly secured joints.
Shop assembly
This is preferred to the extent possible.
Protection of metals
From the finish of the metals to the isolation from other materials that could have an unintended reaction, the designer must consider the long-term environmental impacts on the metal and associated materials. Protection against galvanic action must be provided wherever dissimilar metals are in contact.
Use of sealing materials in fabrication
It is important to comply with sealing and flashing manufacturer recommendations and allow for approved tolerances between sealed components.
General fabrication requirements
To include overall alignment and fit of the installed curtain wall, including trim and accessories, when observed at a prescribed distance and within tolerance stack-up limitations.
Part 3: Execution
This part covers requirements for matching the curtain wall to the building structure, such as erection tolerances and clearances, plus requirements related to field installation, such as welding, sealing, glazing, insulating, protecting, cleaning, and other onsite work.
