If you work in the construction industry or have ever been involved in a skyscraper project, you probably already know what a curtain wall is. It’s a window system chosen for its aesthetic features, energy efficiency, and functional longevity.
If you want to discover more about it, keep reading, as we’ll discuss two types of curtain wall systems, how they’re installed, and what their benefits are!
Key Takeaways
- Curtain walls are non-load-bearing window systems that act as a building’s outer walls. They are designed to resist the elements and allow natural light. Curtain walls are supported by the building’s structural framework.
- Various curtain wall system designs include stick systems for on-site adjustments and unitized systems for rapid installation with pre-assembled modules.
- Curtain walls contribute to a building’s aesthetic appeal, energy efficiency, and performance. They ensure customizable designs, regulate air and water infiltration, and provide thermal insulation and soundproofing.
- Since curtain walls are usually recommended for high-rise buildings, you may want to consider a window wall as an alternative for residential or other low-rise buildings.
What Is a Curtain Wall?
If you’ve ever seen a high-rise building covered in glass, you already know what curtain wall systems are. They’re basically glass covers that act like external walls of a building.
A curtain wall carries no structural load except its own dead load weight. That’s why it is usually made from lightweight materials. As such, it is excellent for multi-storey structures. A curtain wall basically relies on the building’s skeleton for support by transferring lateral wind loads to the main structure.
Did you know that the world’s first building with a curtain wall system was built in the 19th century? Before that, all structures had load-bearing exterior walls.
Over time, as structural steel and reinforced concrete started being used, specialists set on designing buildings with non-load-bearing walls. This opened up numerous design and structural possibilities, including taking advantage of curtain wall systems.
However, it wasn’t until the end of World War II that aluminum wall systems started being used on a large scale.
The Anatomy of a Curtain Wall
A curtain wall system consists of:
- glass panes, which can be double- or triple-pane and feature Low E-coatings
- blocks of stones
- metal panels
- louvers, which are installed where mechanical equipment requires ventilation for smooth operation
- windows and vents, which provide ventilation
- fire-stopping
- weatherstripping
- frame gaskets
- interior sealants
- sound attenuating infill
- back pans, which ensure an additional layer of defense against water infiltration
There are generally two types of curtain wall systems: stick and unitized systems. They are grouped so based on their manufacturing and installation processes.
Stick System Curtain Walls
The stick curtain wall system is akin to a puzzle, assembled piece by piece directly onto the structure. The framing parts are manufactured in the factory, but the glazing panels and the mullions (the frame) are assembled on-site.
This method, often used in low-rise buildings or as part of larger structures, offers a degree of on-site adjustability that is invaluable during the construction process. The stick curtain wall system allows for adjustments to be made as the curtain wall frame takes shape. This ensures that the framed wall aligns with the building’s aesthetic and functional requirements.
This flexibility, however, comes with the need for meticulous surface preparation and installation sequencing. The benefits of such curtain wall systems lie in their customizability, ability to resist air and water infiltration, and properties that protect the building from the elements.
Unitized Curtain Wall Systems
A unitized curtain wall system is a large system consisting of units assembled and glazed in the factory. Then, the curtain wall is shipped to the site and installed on the building.
The installation of these unitized systems is a testament to efficiency. Large modules are hoisted into place and interlocked with the building’s structure, a process that drastically reduces construction time and on-site labor. However, this speed comes with a trade-off: the need for protective measures during transportation. This can increase shipping costs.
The Role of Curtain Walls in Building Efficiency
The efficiency of a building is often judged by what you can’t see — the performance of its envelope. Curtain walls play a crucial role here. Along with the other building’s outer walls, they serve as barriers that manage air and water infiltration while allowing natural light to permeate the building’s interior.
Innovations such as double or triple-glazed vision glass and Low-E coatings significantly increase the system’s energy efficiency and thermal conductivity. Moreover, the insulated glass units formed with double- or triple-pane curtain wall systems allow for additional insulation ensured by the inert gases (usually argon or krypton) added to the space between glass panes.
Smart glazing solutions and dynamic elements like movable sunshades and ventilation flaps respond to environmental conditions, optimizing energy use throughout the day. These features underscore the long-term value and sustainability of investing in energy-efficient curtain wall technology.
However, there’s one thing to consider – most curtain wall systems are made of aluminum, which is a very good conductor of heat. To compensate for the high heat loss, installers have to equip curtain wall systems with thermal breaks usually made of polyvinyl chloride (PVC). They decrease the unit’s thermal conductivity and prevent condensation. Furthermore, the spandrel areas are extremely well-insulated, an aspect that increases their R-value.
Curtain Wall System: Moisture Protection and Soundproofing
The selection of glazing, the precision of curtain wall framing, and the inclusion of drainage – all play a part in directing water away from the building, ensuring that the curtain wall stands the test of time.
According to the Whole Building Design Guide, water can penetrate the exterior glazed curtain walls through these forces:
- gravity
- air pressure difference
- kinetic energy
- capillary action
- surface tension
As such, manufacturers, installers, and structural engineers must consider all five when deciding how to ensure the curtain wall system’s moisture-resistance.
Soundproofing curtain walls implies adding another layer of protection that enhances the comfort of a building’s occupants. The installation of sound attenuating infill can significantly increases the building’s soundproofing features. Ensuring that the construction is as airtight as possible can also contribute to this.
Curtain Walls: Installation Insights
The installation of curtain walls is quite a complicated process, especially if we’re discussing stick systems. Specialists must follow precise steps to achieve a seamless and structurally stable facade. These include establishing control lines to ensure accurate placement to the sequencing of mullions.
As such, curtain wall construction and installation is a meticulous process that takes into consideration numerous aspects.
Here’s an example that can help you understand the process. Let’s say that a building is being equipped with a prefabricated system. Someone needs to be on the floor upstairs to operate the machinery and lift the module.
The workers will lift the module, rotate it, and put the module in place. The next step is to lower it to the module below. That’s it. They will then move to the next module.
Maintenance and Durability of Curtain Wall Facades
The expected service life of these structures can span decades. However, this longevity is only ensured by regular maintenance.
There’s a catch when it comes to curtain wall systems – they need to be designed beforehand with access for maintenance. This is especially true with systems installed on high-rise buildings.
Low-rise buildings can be cleaned and maintained from the ground. On the other hand, tall building structures require swing stage access for repair work and general maintenance. Specialists must equip the roof with davits and fall arrest safety tieback anchors. They also have to install stabilization tie-offs on the face of the wall.
Addressing Common Concerns: Safety and Structural Integrity
When it comes to curtain walls, the specters of safety and structural integrity loom large. These systems are adept at managing wind and gravity loads, transferring them efficiently to the building structure. Through connections at floors or columns, curtain walls ensure the building’s stability even under the most challenging conditions.
Further bolstering their safety credentials are integrated fire safety components like fire-stopping and smoke seals. They help minimize the passage of fire and combustion gases. The inclusion of lateral resistance features also contributes to the overall strength of the system.
Alternatives to Curtain Wall Systems: Magic Window Walls
Let’s say you’re planning to install a window system in your building. You’ve stumbled upon curtain wall systems and window walls – which one to choose?
Well, curtain wall systems are usually recommended for high-rise buildings, while window wall systems are better for residential structures. As such, if the building you’re planning to buy new window systems for is residential, we definitely recommend going for the window wall. This is a significantly more cost-effective option and just as aesthetically pleasing.
If you choose one of the Window Wall options provided by Magic, you won’t get only thin frames and uniquely designed windows, but also highly energy-efficient units that feature the most advanced materials and hardware.
More precisely, Magic window walls feature our patented Parallex Hardware that makes them free of any movable parts or hinges. That’s why our window walls are completely maintenance-free! In addition, they feature our Hybrid Fusion Frame technology – in short, our frames are made of vinyl reinforced with steel and aluminum, which exponentially enhance their strength and durability.
We offer:
- bi-fold door window walls
- sliding door window walls
- French door window walls
- Entry door window walls
- Window window walls
Each type comes with our retractable insect screen and sun shade, as well as our blackout panel that ensures complete privacy.
All these features make our window walls highly durable, energy-efficient, easy to use and clean, and, in short, a true delight!
Summary
As we conclude our exploration of curtain walls, it’s clear that these architectural components are more than just a facade. They are dynamic systems that enhance a structure’s aesthetics, efficiency, and safety. From the sleek profiles of high-rises to the energy-efficient envelopes of office buildings, curtain walls shape not just our skylines but also our experiences within these spaces!
However, if you think a curtain wall system isn’t the best choice for your structure, don’t hesitate to book a free consultation with Magic to learn everything about our Window Wall features!
Frequently Asked Questions
What are curtain walls made of?
Curtain walls are primarily made of lightweight materials like aluminum which contribute to their non-load-bearing characteristic.
How do curtain walls contribute to a building’s energy efficiency?
Curtain walls contribute to a building’s energy efficiency by incorporating features such as double or triple-glazed glass with special coatings and smart glazing solutions, as well as dynamic elements like sunshades and ventilation flaps, all of which help reduce energy consumption.
Can curtain walls protect against water infiltration?
Yes, curtain walls can protect against water infiltration by incorporating drainage systems and sealing details.
How are curtain walls installed?
Curtain walls can be installed using stick or unitized systems, each offering various benefits in terms of flexibility, efficiency, and construction speed. Consider the specific advantages of each method for your project.
Are curtain walls safe and structurally sound?
Yes, curtain walls are safe and structurally sound as they are designed to handle wind and gravity loads, providing lateral resistance and incorporating fire safety components to ensure safety and structural integrity.