Double Pane Window Repair | Allnite Glass

Double pane windows — also called insulated glass units (IGUs) — are standard in most homes and commercial buildings built in the last 30 years. They work by trapping an inert gas (usually argon or krypton) between two panes of glass, providing superior insulation compared to single-pane windows.

When something goes wrong with a double pane window, it usually shows up in one of a few very recognizable ways.

Signs Your Double Pane Window Needs Repair

Fogging or condensation between the panes is the most common symptom. This happens when the seal around the perimeter of the IGU fails, allowing outside air and moisture to enter the space between the glass. Once that seal is broken, the insulating gas escapes and the window permanently loses much of its efficiency.

Other signs to watch for:

• Visible cracks or chips in one or both panes
• Drafts around the window frame even when closed
• Higher energy bills — a failed IGU lets conditioned air escape
• Ice forming on the inside of the window in winter
• Difficulty opening or closing the window (can indicate frame warping from moisture)

Can a Double Pane Window Be Repaired?

It depends on the damage:

Seal failure / fogging — When the seal fails, the IGU itself needs to be replaced. Some companies offer defogging services that drill small holes to remove moisture, but this is a temporary fix that doesn’t restore the original gas fill or full insulating value. The proper repair is to replace the glass unit inside the existing frame.

Cracked pane — A crack in one pane of an IGU compromises the seal and the structural integrity. The entire glass unit needs replacement. Do not leave a cracked double pane window — a broken outer pane exposes the inner pane to impact and weather.

Minor chips or small cracks at the edge — If the crack is very small and caught early, a glazing professional can assess whether a repair resin injection is appropriate. This depends heavily on the location and size of the damage.

Repair vs. Full Window Replacement

Replacing just the IGU (the glass unit) inside an existing frame is significantly cheaper than replacing the entire window assembly. This is the preferred approach when:

• The window frame is in good condition
• The hardware (locks, hinges, sash) works properly
• The damage is limited to the glass unit itself

Full window replacement makes more sense when the frame is rotted, warped, or the window is extremely old and inefficient even by modern standards.

What to Expect from a Professional Repair

At Allnite Glass, we’ve been repairing and replacing double pane window units throughout Clarksville, Nashville, and Hopkinsville since 1949. Our process:

1. Measure the existing IGU — exact dimensions matter for a proper seal
2. Order or fabricate the replacement glass unit — tempered units must be ordered to spec
3. Remove the old unit and clean the frame channel
4. Install the new IGU with proper glazing tape and/or glazing compound
5. Inspect the seal and hardware before finishing

Most standard double pane replacements can be completed within 24–48 hours once the glass is on hand. Tempered or specialty units may require additional lead time.

Serving Clarksville, Nashville, and Hopkinsville

Whether it’s one foggy bedroom window or an entire building’s worth of failed IGUs, our team handles double pane window repair for residential and commercial properties across Middle Tennessee and southern Kentucky.

Call us at (931) 645-2464 or contact us online for a free estimate. We’ll assess whether your windows need a glass-only replacement or a full unit swap and give you an honest recommendation.