Curtain walls are typically classified based on their construction method and the materials used. The most common types of curtain wall systems used in construction are stick-built, unitized, metal or aluminum curtain wall systems, and structural glazing wall systems.
Understanding Curtain Wall Classifications
Curtain walls are non-load-bearing exterior walls that keep weather out while allowing light into a building. They are designed to resist air and water infiltration, absorb seismic and wind forces, and support their own weight. Their classification primarily depends on how they are fabricated and installed.
Primary Types of Curtain Wall Systems
Based on the provided reference and common industry practice, curtain walls are classified into several key types, each with distinct advantages and applications.
Here are the main classifications:
- Stick-Built System: In this traditional method, the curtain wall frame (mullions and transoms) is assembled piece by piece on-site, followed by the installation of the glass or opaque panels into the frame.
- Pros: Highly adaptable to site conditions, lower transportation costs for raw materials.
- Cons: Requires significant on-site labor, installation time can be longer, quality control depends heavily on site conditions.
- Unitized System: This system involves fabricating and assembling the curtain wall units (including glazing and frame) in a factory. These pre-assembled units are then transported to the site and hoisted into place, attaching one unit to another.
- Pros: Faster installation time on-site, higher quality control due to factory assembly, reduced on-site labor.
- Cons: Higher initial transportation costs for large units, less adaptable to unpredictable site conditions.
- Metal or Aluminum Curtain Wall Systems: This classification often overlaps with stick-built and unitized systems as aluminum is the most common material for the framing members (mullions, transoms). Sometimes, 'metal curtain wall' might refer specifically to systems where the framing is prominent or where other metals like steel are used.
- Insight: Aluminum is favored for its light weight, durability, corrosion resistance, and ease of extrusion into complex shapes, allowing for diverse aesthetic designs.
- Structural Glazing Wall Systems: In structural glazing, the glass panels are connected to the building structure using a structural silicone sealant or mechanical fasteners with minimal visible exterior framing. This creates a seamless glass facade.
- Variations: Includes two-sided structural glazing (horizontal or vertical frame members visible) and four-sided structural glazing (frameless exterior appearance).
- Pros: Provides a clean, modern aesthetic; maximizes transparency.
- Cons: Requires specialized sealants and installation expertise; potentially higher cost.
These classifications highlight the different approaches to manufacturing, assembling, and installing curtain walls, each suited for different project requirements and design intents.
Summary Table of Curtain Wall Classifications
| Classification | Description | Installation Method | Key Feature |
|---|---|---|---|
| Stick-Built | Frame and panels assembled on-site. | Piece-by-piece assembly on-site. | High site adaptability. |
| Unitized | Pre-assembled units (frame + panel) fabricated off-site. | Units hoisted and connected. | Fast on-site installation. |
| Metal / Aluminum | Refers primarily to the material of the framing system. | Used in stick-built or unitized. | Material properties (light, durable). |
| Structural Glazing | Glass panels connected structurally with minimal visible exterior framing. | Silicone or mechanical fasteners. | Seamless, frameless appearance. |
Understanding these classifications helps in selecting the most appropriate curtain wall system based on factors like project size, budget, site conditions, timeline, and desired aesthetic.
