Can Windows Be - Resealed __hot__
: Applying high-quality sealant between the window trim and the siding prevents water from rotting the home's structure.
When the internal seal of an IGU breaks, "resealing" is often a misnomer. While some specialized companies offer "defogging" services—drilling tiny holes to vent moisture and resealing the hole—this does not restore the original insulating gas or the window's full R-value. In most cases of IGU failure, experts from Window World and Anglian Home suggest that replacing the glass unit itself or the entire window is the only way to permanently fix the problem and restore energy efficiency. Conclusion
To understand the resealing process, one must first understand the anatomy of a window assembly. Modern residential windows typically utilize double or triple-pane Insulating Glass Units (IGUs). These units are hermetically sealed at the factory with a desiccant material embedded in the spacer between the panes to absorb moisture. This creates a dry, insulating airspace, often filled with argon or krypton gas to reduce heat transfer. Surrounding this glass unit is the sash or frame, which sits within the rough opening of the wall. This assembly relies on a network of seals, gaskets, and caulking to prevent air and water infiltration. The failure of a seal can occur in two distinct zones, and the remedy for each is vastly different.
The Practicality and Limits of Resealing Windows Windows are more than just portals to the outside world; they are critical components of a home’s thermal envelope. Over time, environmental stressors cause seals to degrade, leading to drafts, moisture intrusion, and increased energy costs. While the short answer is that windows be resealed, the effectiveness of the process depends entirely on whether the failure is in the external frame or the internal glass unit. Understanding the Two Types of Window Seals can windows be resealed
| Seal Type | Location | Can It Be Resealed? | Typical Method | |-----------|----------|---------------------|----------------| | (frame to wall) | Around the outer frame | ✅ Yes | Remove old caulk/foam, clean, apply new exterior-grade sealant (silicone, polyurethane, or acrylic latex). | | Glazing seal (glass to frame) | Between glass pane and frame | ✅ Yes (for single-glazed or non-hermetic units) | Remove old putty or rubber gasket, reapply glazing compound or new gasket. | | IGU hermetic seal (between double/triple panes) | Edge of insulating glass unit | ❌ Usually no | Failed IGU seals (fogging between panes) cannot be repaired. The entire IGU must be replaced. |
To determine if resealing is a viable fix, one must distinguish between the two primary sealing mechanisms in a modern window:
This is the sealant (caulk) and weatherstripping around the outside of the window frame where it meets your home’s siding. If this is cracked or peeling, you can reseal it to stop drafts and water leaks. : Applying high-quality sealant between the window trim
The decision to attempt resealing—whether through caulking or glass replacement—must also be weighed against economic and environmental factors. Full window replacement is a significant financial investment. According to industry analysis, the return on investment (ROI) for window replacement is often lower than other home improvement projects, as the energy savings may take decades to recoup the installation costs. Therefore, resealing the perimeter or replacing the IGU offers a much higher immediate ROI. It solves the specific problem of draftiness or fogging at a fraction of the cost.
Resealing the perimeter is a standard maintenance procedure that is not only possible but recommended. The process involves removing the old, failing caulk, cleaning the surface, and applying a new bead of high-quality elastomeric sealant, such as silicone or polyurethane. For interior gaps, weatherstripping can be replaced to restore the airtight seal between the sash and the frame. This form of "resealing" is highly effective, low-cost, and extends the functional life of the window indefinitely. It addresses the symptoms of air and water infiltration without necessitating the replacement of the entire unit.
The second, and more contentious, form of seal failure affects the Insulating Glass Unit itself. This is the phenomenon known as "window fog." When the factory seal around the edge of the IGU fails—often due to age, manufacturing defects, or stress from pressure changes—the inert gas escapes, and moist air enters the space between the panes. The desiccant becomes saturated and can no longer absorb moisture. Consequently, condensation forms on the interior surfaces of the glass, creating a foggy, etched appearance that obstructs the view and diminishes the window's insulating properties (R-value). In most cases of IGU failure, experts from
The short answer is , but the "how" depends entirely on which part of the window has failed. While you can easily reseal the exterior perimeter of a window to stop drafts, a broken seal inside a double-pane glass unit is a more complex issue that often requires professional glass replacement rather than a simple DIY fix. 1. Perimeter Resealing vs. Glass Unit (IGU) Failure
Resealing is a vital part of home maintenance that can extend the life of a window and lower utility bills. However, it is a surface-level fix. It can stop water and air from entering around the frame, but it cannot revive a dead vacuum seal between panes of glass. For homeowners, the first step is an inspection: if the draft is around the edges, reseal it; if the fog is between the glass, it is time for a replacement. Windows with Broken Seals: Should You Fix or Replace Them?