How Do You Make Aluminum Curtain Wall Extrusions?

An extruded metal curtain wall is a thin, metal-framed wall filled with glass, metal panels, or light stone. In modern buildings, aluminum is the preferred metal used in curtain wall frames. This aluminum frame building structure does not bear the building floor or roof loads. 

As a result, the curtain wall's gravity and the wind load get to bypass the building structure, protecting the building from the elements. Moreover, aluminum framed walls were used as long back as the 1930s. They became popular and were built fast post World War II as the aluminum supply was available for non-military use. 

Different Kinds of Curtain Wall Systems

There's a huge range of available curtain wall systems. These may be a manufacturer's standard offerings or specialized or custom walls per client project requirements. Custom walls are highly cost-competitive and have standard systems for expanding wall areas. Aluminum and glass-based curtain wall systems can be incorporated into standard or custom systems. Consultation with experts in custom wall design is important for incorporating aluminum curtain wall frame systems. 

Read on for a brief description of popularly used curtain wall framing methods. Curtain walls are classified based on the methods of their installation and fabrication in this way:

Stick systems: In this system, glass or other opaque panels are utilized by connecting them to the curtain wall frame.

Unitized systems: The unitized system comprises factory assembled and glazed curtain walls made of large units. These get shipped to a site where they get erected on buildings. Moreover, you can choose between vertical and horizontal aluminum frames that join with their adjoining modules. Typically, the modules will be one story tall and one module wide, and most units have a width between five and six feet.  

Curtain walls are also classified as:

• Pressure equalized systems
• Water managed systems

The unitized and stick-built systems are designed to become part of the building's design as interior or exterior or interior glazed systems. 

Interior glazed systems are helpful for glass and opaque panel installation using curtain wall opening from the building's interior. Unfortunately, you don't get many details for an interior glazed system due to the concern of air infiltration in these systems.

When there are a few obstructions and the application provides complete access to a curtain wall's exterior, interior-faced extrusions are used. High-rise internal glazing is helpful as it is easy to access and has more favorable logistics for replacing a swing stage. 

In external glazed systems, the exterior of the building is used as a swing stage, giving access to the curtain walls' exterior for replacement and repair. Moreover, the glass or opaque panels also get installed from the curtain walls exterior. 

Specific curtain wall systems are glazed from both the interior and the exterior. Typically opaque channels are installed with

• Metal panels
• Opacified spandrel glass  
• Terra cotta
• FRP (fiber-reinforced plastic)
• Thin stones

And other materials.

Using the laminated insulating glass with both sides can usually get fixed or glazed window frame units incorporated into window wall framings. They may be operable.

Various types of Spandrel glass can be insulated glass. It can also be laminated or monolithic. 

Using film or paint or ceramic fitting helps to make spandrel glass opaque. They are applied on unexposed surfaces or to provide an enclosed space and an enclosed space behind the glass. This shadow box construction gives an illusion of depth and is highly desirable.

Metal panels

Various metal panels can be used for simple steel metal panels, aluminum metal panels, or panels made from other non-corrosive metals. These thin or composite panels comprise two aluminum sheets surrounding a plastic internal layer. All these layers are thin, making the unit lightweight. In other words, panels comprise metal sheets with a solid insulation frame and optional inner metal sheets between them.

Stone panels

It's best to use thin granite to get stone panels. However, it isn't advisable to use marble as this stone can undergo deformation because of hysteresis. Moreover, it is necessary to have a curtain wall comprising an essential part of the building's wall system. It's required to get an intricate integration with the adjoining elements like the other wall cladding base on the roof of the walls to get a proper installation. 

Different Types of Curtain Wall Systems 

Various types of Aluminum curtain wall systems include:

• Face-sealed wall curtain systems: These provide resistance to the elements.
• Water-managed wall curtain systems:  They provide highly reliable water-managed systems, protecting the building from the direct impact of wind and rain.
• Pressure-equalized rain screen wall curtain systems: Pressure-equalized rain screen wall curtain systems are highly resistant to water infiltration and air inflow. Pressure-equalized rain screen systems block all the forces capable of driving water along a barrier. 

The curtain wall systems with rain screen systems have glass on the inner side of the glazing pocket or the interconnecting gasket that functions as an airtight barrier. The outer face of the glass has different glazing materials, while the exposed and external aluminum framing is like the rain screen that keeps away the water. Due to the interior air chamber and the exterior rain screen, a pressure-equalization chamber gets formed in the glazing pocket. It proves helpful for lowering water penetration by equalizing the pressure difference with the rain screen, which can lead to water gushing inside the system. If a small amount of water penetrates the system, it just weeps out from the exterior.  

Water-managed systems also have drains and weep into the glazing pocket. But, they have a spandrel unit that does not have an air barrier, and a significant amount of water gets forced into a system that goes out through weeping. Because of no air, a pressure differential may form between the interior and the glazing pocket, forcing water to move vertically higher than internal gaskets. This can lead to leaks. Weep holes in this system help drain water entering a glazing pocket. 

In a pressure-equalized system, they act to allow air movement within the space between the glazing pocket and the exterior. The other functions include the weeping of water. You can easily point out a pressure-equalized rain screen wall curtain system with an isolated, airtight glazing pocket in each glass unit. Seals or plugs in the gaps between screw seal lines at aluminum panel intersections help to do this isolation. Also, check the other details, such as:

• Spandrels
• Shadowbox

An interface with adjoining construction must have continuity with the air barrier and rain screen for proper functioning in a pressure-equalized rain screen aluminum curtain wall framing system.

Some aluminum curtain wall systems are designed to appear like face-sealed barrier walls. So, you will notice a perfect continuity of seals between the frame and the glass units to perform better. But, such seals may not be in the long term and, therefore, should not be used. If you want to get more information about this, please feel free to reach out to us at WJW Aluminum.