How to Repair a Cracked Double-Pane Window

Double-paned windows are designed for energy efficiency, consisting of two glass panes separated by a metal spacer and sealed at the edges. Between these panes is an inert gas, like argon, which helps minimize heat transfer. If one pane cracks, the gas escapes, and the window loses its insulating properties.

While you might picture a baseball shattering a window, double-paned glass can crack over time due to wear, temperature changes, or even the heat trapped by curtains. Glass specialist Rich Rosenfeld explains how even simple actions, like closing curtains, can contribute to cracks by preventing heat from dispersing.

Here’s a look at your options for repairing a double-paned window.

Repair Options for Double-Pane Windows

1. Sash Replacement
   Sometimes, you don’t need to replace the entire window unit—just the sash. If your window frame is still in good condition and the manufacturer offers replacements, a new sash could be a cost-effective option.
2. Glass Assembly Replacement
   You may also be able to replace just the glass. Some companies provide custom glass replacements that fit into your existing sash. This is often a more affordable option than sash replacement and involves a professional technician removing the damaged glass and installing the new one.
3. Full Window Replacement
   If the frame is damaged or too old, or if parts are no longer available, replacing the entire window might be necessary. While this is usually the most expensive option, it could be the best choice in the long run.

Tips for Choosing Replacement Materials and Services

• Value over cost: Choose high-quality materials and services to ensure longevity and better performance, even if the initial cost is higher.
• Compatibility: Ensure that the replacement parts are compatible with your existing window. An expert can help you choose the right materials to avoid damage or inefficiency.
• Warranty: Opt for materials and services that offer a solid warranty to protect your investment from defects or issues.
• Get multiple quotes: Obtain estimates from several companies before making your final decision. Verify that they are properly licensed and insured.

The Glass Replacement Process

Here’s a quick overview of how the glass replacement works:

1. Measuring the Window
   Rosenfeld measures the window to determine the dimensions for the new glass. This includes width, height, and thickness, ensuring a proper fit.
2. Manufacturing the Glass
   The glass is custom-cut to the measurements. The factory uses specialized machines to score, snap, and clean the glass, then assembles it with a metal frame and seals it with an insulating layer and polysulfide sealant.
3. Removing the Old Glass
   After the new glass arrives, Rosenfeld removes the sash and window stops, cuts through the sealant, and carefully presses the window assembly out of the frame.
4. Installing the New Glass
   To install the new glass, a bead of caulk is applied around the sash’s inner perimeter, the glass assembly is placed in the caulk, and the stops and hardware are reinstalled.