Colorado Springs homeowners treasure the character that leaded glass brings to tall entryways, stairwell landings, and transom openings. From the historic homes of the Old North End to properties near the Broadmoor, leaded glass windows in Colorado Springs add a warmth and craftsmanship that ordinary glazing simply cannot match. Yet tall panels—those dramatic six- and eight-foot installations that define a grand foyer—face a structural challenge unique to our Front Range climate: bowing.

Bowing is the slow outward or inward curve of a leaded panel as gravity and temperature cycling take their toll on the soft metal framework. Understanding why it happens and how to prevent it can save homeowners from costly repairs and preserve the beauty of their glass for decades.

What Causes Leaded Glass Panels to Bow

The lead came that holds each piece of glass in place is a soft metal by design. It needs to be pliable enough to wrap around varied glass shapes and absorb minor expansion and contraction. That same softness, however, means lead gradually fatigues under sustained weight. After eighty to a hundred years of seasonal temperature swings—expansion in summer, contraction in winter—the cumulative stress weakens every solder joint, and the panel begins to sag under its own weight.

Tall panels are especially vulnerable because their height magnifies the gravitational force acting on the lower sections. A window that stands six feet or taller places significantly more load on its lower lead joints than a small transom or sidelight. When the steel reinforcement bars that originally supported the panel corrode or detach over time, nothing remains to counteract that downward pull, and the glass begins to bow outward.

According to guidance from the American Institute for Conservation’s stained glass conservation resources, determining what glass and lead are original versus what has been replaced over the years is a critical part of any restoration. A panel that has been repeatedly re-leaded with heavier or incompatible came can develop uneven stress points that accelerate bowing in leaded glass windows in Colorado Springs and elsewhere.

Why Colorado Springs Accelerates Bowing

Living at over 6,000 feet elevation on the Front Range means leaded glass windows in Colorado Springs endure some of the most demanding conditions of any American city. Our high-altitude UV exposure is roughly 25 percent more intense than at sea level, which degrades the putty and cement that seal lead joints over time. Once that sealant breaks down, moisture reaches the lead came, accelerating corrosion and further weakening the structural matrix.

Day-to-night temperature swings in Colorado Springs can easily reach thirty or forty degrees, particularly in spring and fall. Each cycle causes the lead to expand and contract, and over decades those micro-movements accumulate. Homes in neighborhoods like the Old North End and those lining the tree-shaded streets near Garden of the Gods often contain original leaded glass that has been cycling through these temperature changes for a century or more.

The good news is that proper reinforcement and regular maintenance can prevent bowing even in our challenging climate. When we design and install leaded glass windows in Colorado Springs, we engineer every panel to handle the specific conditions it will face.

Signs Your Tall Panels Are Bowing

Catching bowing early makes restoration far simpler and less invasive. We recommend that homeowners visually inspect their leaded glass from both inside and outside at least once a year, looking for these indicators:

  • Visible curvature—stand to the side and look along the face of the panel; any curve greater than an inch or two needs professional attention
  • Gaps between the glass and the surrounding frame where the panel has pulled away from its opening
  • Cracked glass pieces near the edges, which can occur when a bowed panel twists and places stress on individual pieces
  • Sagging or detached horizontal lead lines, especially in the lower third of a tall panel
  • Rattle or movement when the window is opened, closed, or subjected to wind

If any of these signs are present, the panel should be evaluated by a professional before the damage progresses. Attempting to flatten a bowed panel without proper training almost always results in broken glass and further structural damage.

How We Prevent Bowing in New Installations

Prevention begins at the design stage. Every tall panel we craft includes steel or copper reinforcement bars embedded into the lead matrix at regular intervals. These bars are tied to the panel’s perimeter frame and distribute the panel’s weight across its full height, preventing the gravitational sag that causes bowing.

We also select lead came hardness based on the panel’s dimensions. For tall installations, we use a harder extruded lead in the horizontal members that carry the most load, paired with softer came in the verticals to maintain the flexibility needed for glass expansion. This combination balances strength and resilience in a way that factory-made or hastily assembled panels do not.

Our portfolio of completed commercial and residential projects demonstrates how properly engineered tall panels maintain their flatness and structural integrity even after years of exposure. Each project is designed for its specific opening, orientation, and environmental conditions.

Restoring Bowed Panels

When a panel has already bowed, restoration involves carefully removing the window, flattening it on a level workbench, and re-leading the compromised sections. We replace fatigued came with new material matched to the original profile, re-solder every joint, and reinstall or upgrade the reinforcement bars. The panel is then re-cemented to restore weatherproofing and structural rigidity before being reinstalled.

This is meticulous work that demands an understanding of both historical construction methods and modern conservation standards. For homeowners seeking expert care for leaded glass windows in Colorado Springs, working with a studio that has experience restoring tall, bowed panels ensures that the window’s historic character is preserved while its structural integrity is renewed.

Ready to Protect Your Leaded Glass Windows?

If you have tall leaded glass panels in your Colorado Springs home—whether they are original to a century-old property or a more recent installation—do not wait for bowing to become visible. A professional assessment can identify early signs of fatigue and recommend preventive reinforcement before damage occurs. Leaded glass windows in Colorado Springs deserve the same care and attention as any other architectural feature of your home.

Contact Commercial Art Glass today to schedule a consultation. We will evaluate your panels, discuss reinforcement options, and provide a plan to keep your leaded glass flat, beautiful, and structurally sound for generations to come.