Curtain Wall Installation: A Complete Guide for Commercial Buildings

Curtain wall installation is what gives a commercial building its glass skin without asking that skin to carry any weight. Done right, it keeps water and wind out for 30+ years. Done wrong, it’s the reason a facade leaks in year two. 

This guide walks through the systems, the step-by-step process, the standards, and the mistakes we see most often on real jobs, not just textbook theory.

Quick Summary: Curtain Wall Installation at a Glance

Here’s the short version before we get into detail.

What Is Curtain Wall Installation?

Curtain wall installation is the process of anchoring a lightweight, non-load-bearing façade, usually aluminum framing with glass or metal panels, to a building’s structural frame, one floor at a time.

The wall itself carries none of the building’s weight. Instead, its anchors transfer wind, seismic, and self-weight loads straight back into the floor slabs or steel structure behind it. 

That’s the whole point of the system. S continuous, weatherproof skin that lets architects use huge amounts of glass on towers that would otherwise need solid masonry.

You’ll mostly see it on buildings four stories and up, though smaller commercial projects use it too, purely for the look and the daylight.

Curtain Wall vs. Window Wall vs. Storefront

People mix these up constantly, so here’s the quick distinction:

1. Curtain wall. Spans past the floor slab, hung from anchors, used at any story of the building
2. Window wall. Sits between floor slabs, typically used from the second floor up
3. Storefront. Ground-floor only, lighter-duty framing, shorter spans

Types of Curtain Wall Systems

There are two main types of curtain wall systems, stick-built and unitized.

1. Stick-Built Curtain Wall Systems

Stick-built systems are assembled on site, starting with vertical mullions, then horizontal transoms, glass, infill panels. This gives flexibility for tight or unusual openings. But it takes more site labor and more time.

2. Unitized Curtain Wall Systems

Unitized systems arrive as complete, factory-glazed panels, usually one floor high, get lifted into place by crane or hoist. There’s less scaffolding, faster schedules, and tighter quality control since fabrication happens indoors.

3. Semi-Unitized (Hybrid) Systems

Semi-unitized panels are partially built in the factory, then finished on site. It’s a middle ground for projects where a full unitized system isn’t practical, but a plain stick build is too slow.

How Is Curtain Walling Installed? The Step-by-Step Process

Curtain walling is installed in a fixed sequence, shop drawing review, structural verification, control-line layout, anchor installation, framing and glazing, then sealing and testing. All this with each step checked before the next one starts.

Step 1: Shop Drawing Review

The fabricator’s shop drawings, every mullion, transom, anchor, and panel, get checked against the architectural and structural drawings before anything ships. This is where design mismatches get caught, not on site with a crew standing around.

Step 2: Structural Verification and Tolerances

The crew confirms the building structure is within tolerance using as-built surveys. A concrete slab that’s an inch off its intended line can throw off the entire facade plane. So this gets checked before anchors go in.

Step 3: Control Lines and Layout

Benchmarks and offset lines are marked on every floor so the wall stays one continuous, flat plane from top to bottom. This layout gets checked by more than one person. A small error here compounds on every floor above it.

Step 4: Anchor and Bracket Installation

Anchors are set at the marked points and bolted or welded to embeds in the slab or steel. Anchor position has to be exact. Forcing a bolt to fit with extra washers is a known cause of facade failures later on.

Step 5: Framing and Glazing

For stick systems, mullions go up first, then transoms, then glass. For unitized systems, complete panels get hoisted and locked into the anchors floor by floor. Gaskets, thermal breaks, and sealants go in as each unit is set.

Step 6: Mock-Up and Field Testing

A representative mock-up section, typically two stories tall, gets tested for air infiltration, water penetration, and structural performance. Field-installed sections are re-tested afterward to confirm real-world performance.

Materials and Components of a Curtain Wall System

A curtain wall is built from a small set of components, and getting any one of them wrong undermines the whole assembly.

1. Aluminum framing (mullions and transoms), occasionally steel for larger spans
2. Thermal breaks, polyamide or polyurethane strips that stop heat transfer through the frame
3. Infill panels; glass, spandrel, metal composite material, or stone
4. Anchors and brackets; connect the frame to the building structure
5. Gaskets and structural sealants, seal joints and, in structural glazing, hold the glass itself
6. Drainage components, weep paths that let each unit shed water individually

Standards and Testing Every Curtain Wall Should Meet

Every commercial curtain wall installation should be tested and specified against recognized industry standards, not just built to look right.

1. ASTM E283, E330, and E331, air infiltration, structural performance, and water penetration testing
2. AAMA design and performance-grade guidelines, from Light Commercial up to Architectural grade
3. NFRC ratings for U-factor and solar heat gain, used to confirm energy performance
4. FGIA field testing standards for installed systems
5. Energy codes referencing ENERGY STAR and DOE guidance for commercial building envelopes

Meeting these isn’t paperwork. It’s the difference between a facade that performs for thirty years and one that leaks in the first storm season.

Common Curtain Wall Installation Mistakes

Most curtain wall failures trace back to a short list of avoidable errors on site, not design flaws.

1. Forcing anchors into the wrong position with extra washers or shims instead of correcting the layout
2. Skipping, rushing mock-up testing to save time before full production
3. Poor thermal break detailing at corners, causing condensation and energy loss
4. Treating drainage as a whole-wall system instead of testing each unit individually
5. Missing perimeter fire-containment details that don’t match the referenced UL system

Pros and Cons of Curtain Walls

Curtain walls bring in daylight and cut structural weight, but they also carry real trade-offs worth planning for.

Why Choose Starveil Windows for Curtain Wall Installation

We’ve been designing and manufacturing aluminum window, door, and facade systems for 28 years, and curtain wall is where that experience really shows.

Our 45,000 m² factory in Foshan has delivered systems for 1,500+ projects across 118 countries. And every curtain wall product we make is certified to NFRC, CSA, CE, and AS2047 standards. 

That means the anchors, thermal breaks, and glazing details in this guide aren’t theoretical for us, they’re what we specify and build every day.

Ready to Start Your Curtain Wall Project?

Curtain wall installation only performs the way it’s supposed to when the design, materials, and site execution are all handled by people who’ve done it before.

Talk to our team at Starveil Windows about your commercial facade specs, and get a free quote now.

FAQs

How is curtain walling installed?

Curtain walling is installed by reviewing shop drawings. Then verifying structural tolerances, setting control lines. Fixing anchors, then adding the framing, glass, and sealant, followed by field.

What are the two types of curtain wall systems?

The two main types are stick-built systems, assembled piece by piece on site. Unitized systems, which arrive as complete factory-glazed panels ready to be lifted into place.

What are the disadvantages of curtain walls?

The main disadvantages are a higher upfront cost. The risk of thermal bridging if the framing detail is poor. And a dependence on experienced installers.

What are the construction details of a curtain wall?

The core construction details are the mullion-and-transom frame. The anchor points connecting it to the structure. Thermal breaks between interior and exterior aluminium. And the drainage path that lets each panel shed water on its own.