Curtain Wall Installation in Centennial, CO
What curtain wall installation is and why commercial buildings need it
A curtain wall is a non-structural glass and aluminum skin hung on the outside of a commercial building frame. It encloses the structure and its floors without carrying the building's weight. Unlike load-bearing walls, curtain walls transfer wind and seismic forces back to the structural frame behind them.
Curtain walls serve three jobs at once: they keep weather out, they control heat and light penetration, and they define the building's visual footprint. Most mid-rise and high-rise commercial properties use them because they span large floor-to-floor heights, accommodate flexibility in floor plates, and let tenants control interior layouts without moving glass.
You need a curtain wall installed when you're building new, replacing an existing envelope, or upgrading glazing after damage or code changes. Property managers sometimes call when an existing system begins to leak or fails to meet current energy or wind-load codes.
Stick-built vs. unitized systems: which one fits your project
Stick-built and unitized curtain walls differ in how components arrive at the jobsite and how fast they install.
Stick-built curtain wall systems
Stick-built means aluminum mullions and transoms (vertical and horizontal extrusions) arrive at the site as individual pieces. Glazing crews assemble the frame in place, inserting Insulated Glass Units (IGUs) and applying structural silicone sealant as they work upward. This method lets you adapt to field conditions and small layout changes. It typically costs less upfront because less happens in the fabrication shop. Lead times are shorter because the system doesn't require full pre-assembly. Trade-off: installation takes longer on site because every piece is hand-fitted and sealed.
Unitized curtain wall systems
Unitized systems arrive as prefabricated modules, two or four stories tall, with glass, gaskets, and structural sealant already installed in the shop. Crews bolt the units to the structural frame and seal joints between units at the site. This dramatically cuts installation time, especially on tall buildings. Units are weathered and tested before they ship, so field defects drop. Trade-off: lead time is longer because the entire system must be fabricated off-site. Changes during fabrication cost more. You need a clear, final design before orders lock.
Choose stick-built if your timeline is short, your design may change, or your budget is tight. Choose unitized if your schedule is long, your building is tall, and your design is locked.
How long does curtain wall installation take on a mid-rise building
Installation speed depends on system type, building height, window-to-wall ratio, weather, and how occupied the building is.
Stick-built systems on a typical mid-rise (10 to 20 stories) average 8 to 16 weeks from first mullion to final caulk joint, assuming good weather and no rework. Glazing crews work one or two floors at a time, which means the project occupies the site for months.
Unitized systems compress that to 6 to 12 weeks because units pre-install much faster. Large crane time becomes the bottleneck instead of hand-labor hours.
Once glass arrives, crews still must verify each unit against shop drawings, check alignment, install gaskets and pressure plates, apply glazing sealant, and run air and water resistance testing. None of that gets skipped even if the system is fast.
Weather delays the schedule. Rain stops caulking. Wind keeps crews off scaffolds. If the building is occupied, early-morning and off-peak windows shrink available hours, which stretches the timeline by 25 to 50 percent.
What lead time should you expect for fabrication and installation
Lead time is the delay between order lock and first shipment. It varies sharply by system type and market demand.
Stick-built systems typically ship within 4 to 8 weeks of order. The shop cuts mullions to length, preps them, and bundles them. Less complex work means faster turnaround.
Unitized systems often require 10 to 16 weeks because the shop assembles the entire module, installs glass and gaskets, applies sealant, weathers the unit, and runs ASTM E283 air infiltration testing and ASTM E331 water resistance testing before it ships. If your design requires custom colors, special glass coatings like Low-E for solar heat control, or fire-rated glazing, add another 2 to 4 weeks.
Plus lead time, installation onsite runs 6 to 16 weeks depending on your system choice and building size. Total project duration from signed contract to ribbon-cutting is typically 4 to 8 months for stick-built work and 5 to 10 months for unitized systems.
Glass supply and aluminum extrusion demand swing those windows. During market peaks, lead times stretch. Planning your curtain wall project 6 to 12 months before construction starts gives you the best pricing and shortest wait.
What causes curtain wall leaks and how to prevent them
Curtain wall leaks are not accidents. They happen because water gets past the seal.
The most common cause is failed structural silicone sealant at the junction between the frame and the glass, or between mullion segments. Silicone shrinks and splits over time, especially if installers applied it in direct sun or in cold conditions that prevent proper cure. Sealant also fails when glass-to-frame movement exceeds the joint's flex design, which happens on tall buildings in wind or thermal cycling.
Second: improper gasket seating. Pressure plates and glazing gaskets must compress uniformly across the entire glass edge. If a gasket is pinched, twisted, or cut during installation, water finds the gap. Gaskets also harden and lose sealing properties after 15 to 20 years, especially in Colorado's dry climate with intense UV exposure.
Third: water entry at mullion joints and at slab edges where the curtain wall ties to the structure. If weep holes or internal drainage channels clog with dust or silicone residue, water pools behind glass and leaks inward.
Fourth: design flaws. If the mullion profile has no proper water management zone, or if the sealant joint is too wide or too narrow for the materials used, leaks become inevitable.
Prevention starts before installation. Using ASTM E331 and ASTM E547 water resistance testing on mock-ups confirms the design will shed water. During installation, apply structural silicone in the right temperature range, with proper joint width and sealant tooling. Compress gaskets evenly. Keep weep holes and drainage channels clear. After installation, re-test the completed system with ASTM E1105 curtain wall water penetration testing to catch leaks before they damage the building.
Signs a commercial curtain wall needs repair or replacement
Don't wait for a tenant complaint to notice curtain wall trouble.
Look for visible cracks in glass, especially spiderweb patterns radiating from a point. That's impact damage or stress from movement beyond the glass's design. Tempered glass (ASTM C1048) cracks in the field and creates safety hazards. It must be replaced.
Watch for water stains on the floor or wall behind the glass, especially after heavy rain or snowmelt. That means sealant or gaskets have failed, and water is entering the building. Interior framing and insulation behind wet glass rot fast. Act quickly.
Look at the mullion frame for corrosion or white powder on aluminum surfaces. That's oxidation, which weakens the frame and eventually compromises structural integrity at connections.
Check the sealant joint. If it's cracked, shrunk, or pulling away from glass or aluminum, water will follow. Sealant older than 15 to 20 years often needs replacement even if no active leak exists.
Listen during wind. A rattling or popping sound means something is loose: a gasket, a pressure plate, or the connection between the frame and building structure. Loose parts amplify wind loads and accelerate failure.
If you can press the glass and feel flex or movement in the frame, the curtain wall may have lost alignment or a connection bolt has loosened. That reduces the system's ability to resist wind and seismic forces.
When you spot any of these, call a NACC-certified glazier to diagnose the scope. Small repairs can stop a small leak. Large-scale sealant failure or structural damage might require partial or full replacement. The sooner you know, the sooner you protect your building and your tenants.
How much does commercial curtain wall installation cost per square foot
Cost per square foot varies by system complexity, glass type, aluminum alloy grade, and market conditions. We can't quote a single number because the variables swing the price widely.
Stick-built systems with standard aluminum extrusion (6063-T5 or 6063-T6 alloy), basic clear IGUs, and standard silicone sealant typically fall in the mid-range. Unitized systems cost more per square foot because of the prefabrication labor, testing, and shipping logistics.
Special glazing drives cost up: low-E coatings for solar heat control, laminated safety glass (ASTM C1172) for security, fire-rated glazing for code compliance, and high-performance IGUs with multiple panes and inert gas fill all add material cost. So does custom anodizing or painted finishes on aluminum.
Thermal breaks (reinforced polyamide or polyurethane inserts in the mullion) improve energy performance and meet ASHRAE 90.1 and IECC energy codes, but they cost more than aluminum-only frames.
Wind loads and seismic requirements in your location drive structural frame size and cost. Colorado buildings designed to AAMA CW or Architectural performance grades need heavier frames than lower-performance systems.
Labor cost depends on crew productivity, weather delays, and site accessibility. High-rise work with limited crane and scaffold access costs more per square foot than ground-level work.
The honest answer: get three bids from glaziers who've done similar work in your market. Pricing spreadsheets without site details are fantasy. Real quotes come from walk-throughs and shop drawings.
AAMA performance grades and why they matter for your building
AAMA performance grades measure how a curtain wall resists wind pressure, water penetration, and air leakage.
AAMA LC (Light Commercial) is the entry grade. It's for low-wind areas and simple storefronts. It has loose air and water tolerances. Most commercial projects won't use it.
AAMA CW (Curtain Wall) is the workhorse standard for mid-rise and commercial buildings. It balances cost and performance. It passes ASTM E330 structural performance testing at defined wind pressures, ASTM E283 air infiltration limits, and ASTM E331 or E547 water resistance testing. Most projects specify CW.
AAMA Architectural (AW) is the high-performance tier. It's for tall buildings in high-wind zones, buildings that must meet strict energy codes, or owners who want zero air leakage. Testing pressures are higher, gasket materials are premium, and sealant specs are tighter. Architectural grade costs 15 to 25 percent more than CW but performs better in wind and thermal conditions.
Your building code and wind zone determine which grade you need. Colorado's IBC Chapter 24 (Glass and Glazing) and local amendments specify minimum performance. A 15-story building in downtown Denver in an exposed location will need Architectural grade. A smaller office park in a sheltered suburb might meet code with CW.
Choosing the right AAMA grade upfront avoids costly redesigns midway through fabrication. Get the code analysis done before the design is locked.
Difference between curtain wall and storefront glazing systems
Curtain walls and storefronts both use glass and aluminum, but they're engineered for different jobs.
A curtain wall spans floor-to-floor on the outside of a building, often 12 to 20 feet tall per section. It's hung from the structural frame and carries no load except its own weight plus wind and seismic forces. Mullions are thicker, frames are deeper, and sealant joints are engineered to manage movement over decades. Curtain walls survive high wind, thermal cycling, and are built to AAMA CW or Architectural performance grades.
A storefront glass installation sits at ground level, typically 12 to 15 feet tall, and is bolted directly to the structure. Frames are lighter because they don't span multiple stories or resist the wind pressures a tall wall does. Storefronts are engineered to AAMA LC or CW grades, depending on wind exposure. They use thinner gaskets and are built for shorter service life before refurbishment.
In practice: a curtain wall is the building envelope. A storefront is the ground-floor entry. Different codes, different engineering, different materials, different costs.
When you replace a storefront, you're not automatically ready to replace a curtain wall above it, and vice versa. Each requires its own engineering and installation plan.
Why Element13 handles curtain wall installation differently
Element13 brings union-trained craftsmanship and NACC Master-Certified glaziers to every curtain wall install. All our glaziers are signatory to the Glaziers Union Denver, which means they've completed formal apprenticeships and ongoing training in proper glazing practice. That's not a credential everyone carries.
We own in-house fabrication and assembly capability, which means we can run ASTM E283 air infiltration testing and ASTM E331 water resistance testing on your system before it ships. We catch design and build problems in the shop, not after the glass is on your building. Most glaziers buy their mullions and glass from suppliers and install them blind. We fabricate custom shapes, test units, and stand behind them.
Our leadership team has more than 40 years combined glazing experience. That's not hype. That's the difference between a crew that has seen what goes wrong and one that hasn't.
We're commercial-only. We don't split attention between residential and commercial work. That means we understand commercial timelines, union labor requirements, occupied building constraints, and the codes that govern your project. We speak the language of contractors and property managers because that's all we do.
We're DBE, EBE, and WMBE certified through the City and County of Denver. If your project has diversity or equity requirements, we can help you meet them.
We communicate proactively. When a problem surfaces, you hear about it immediately, with options and a fix timeline. We don't bury scope creep or surprise you with delays.
We've logged zero major safety incidents. That matters on occupied buildings and in tight urban settings. Safety is not a slogan here. It's a baseline.
Most of all: we take accountability for the work. We don't hand off installation and disappear. If the curtain wall needs adjustment, repair, or diagnostic testing after installation, we're the ones who do it.
Frequently Asked Questions
We run ASTM E1105 curtain wall water penetration testing after the system is sealed. That test applies water under pressure to the exterior while pressure differentials pull air through the system. If water shows up on the inside, we identify where and why, then fix it before the project is signed off. This is non-negotiable. A curtain wall that hasn't been tested is a liability.
Yes, but only if the damage is localized to gaskets, sealant, or individual glass units. A cracked glass pane gets replaced with a new IGU that matches the original specification. Failed sealant gets cut out, the joint cleaned, and new structural silicone applied. A deteriorated gasket comes out and a new one seats in its place. But if the mullion frame is cracked, corroded, or the structural connection is compromised, you're looking at section replacement, which means removing multiple units, replacing the frame, and reinstalling glass. That's a larger scope. Element13 can assess what's actually needed and give you a repair-vs-replace recommendation based on the damage.
Curtain walls are tied to the building's structural frame at specific anchor points. If the structure changes, the curtain wall anchors may need relocation, and sections may need redesign. That's a commercial glass replacement or upgrade project, not maintenance. It requires structural analysis and code review. It's doable but not simple. That's why it's critical to get the initial design right and lock it before fabrication starts.
There's no blanket code mandate for regular curtain wall recertification, but smart building managers schedule visual inspections every 3 to 5 years, looking for sealant degradation, gasket hardening, corrosion, or any visible damage. If you spot trouble, diagnostic testing (air and water resistance) tells you if the system still meets its original AAMA grade. If it fails, repair or replacement gets budgeted and scheduled. Ignoring a slow-failing curtain wall turns a small repair into a big replacement.
Warranty terms depend on the contract and the materials. Structural silicone sealant is typically warranted for 10 to 20 years against failure if installed correctly. Glazing gaskets and pressure plates typically carry 5 to 10 year warranties. The aluminum frame has a manufacturer warranty that varies by alloy and finish. Workmanship warranties cover Element13's installation labor and are typically 2 to 5 years. Get the warranty schedule in writing before work starts. We'll back our work, and we'll make sure you have paper on the material warranties too.
Yes, with planning. We schedule work around tenant operating hours, use early-morning and off-peak windows, and coordinate with your property manager and building operations. We control dust, manage scaffold placement so it doesn't block building entries, and establish clear communication channels for issues. On multi-tenant buildings, notification to affected tenants goes out in advance. On very sensitive properties, we may phase the work in smaller sections to minimize disruption. It takes longer and costs more, but it's the standard practice for occupied commercial projects.
When Glass Door Problems Can't Wait Contact Element13
Your building's glass front entrance doors handle hundreds of entries daily. When they fail, have cracked glass, broken closers, or hardware that won't engage, it's not just inconvenient, it's a security risk. Property managers and general contractors know that entrance problems reflect poorly on the entire building and create liability concerns.
