Why Fix Double-Pane Glass?
Over time, the seal around your IGU can fail, letting in moisture or dirt and silently stealing your home’s insulation. A quick repair can:
- Restore Clarity: Wave goodbye to that permanent fog or trapped debris.
- Save Energy: Stop drafts and curb heat loss without replacing the entire window.
- Stretch Your Budget: Repairs often cost half (or less) of a full window swap.
1. Look for These Warning Signs
- Foggy or Misty Glass: Moisture trapped between the panes means the seal is toast.
- Specks of Dirt or Debris: Tiny particles inside tell you air—and whatever it’s carrying—has snuck in.
- A Noticeable Draft: If you feel cold air near the glass, the insulating air cushion is gone.
- Unwipable Interior Haze: You can’t clean it off, because it’s inside.
- Sticking or Hard-to-Operate Sashes: Warping from moisture can make windows jam.
2. How Glass Repair Works
A. Defogging (Drying)
- Drill a pin-hole in the outer pane corner.
- Suck out moisture with a vacuum tool.
- Inject desiccant to soak up leftover dampness.
- Seal the hole with clear epoxy.
Time: About 30–60 minutes per pane
Cost: $75–$150 per pane
Good For: Single panels with light fogging; adds 2–5 years of clarity
B. Resealing & Spacer Refresh
Remove old putty or sealant around the glass edge.
- Press in fresh, weather-tight seal (butyl or silicone).
- Swap out the metal spacer bar and its dried-up desiccant for a new one.
Time: 1–2 hours per unit
Cost: $100–$200 per pane
Good For: Early seal failures; extends lifespan 3–7 years
C. Partial Glass Replacement
- Pull out the damaged inner or outer pane.
- Slide in a fresh sheet of insulated glass.
- Re-seal in the existing frame.
Time: 2–3 hours per unit
Cost: $150–$300 per pane
Good For: Units with multiple or severe seal failures
D. Full Window Swap
When frames are warped or the IGU damage is extensive, replacing the entire window often makes sense.
Time: 2–4 hours per window
Cost: $300–$600 per window
Good For: Old, rot-ridden, or repeatedly failing installations
3. Repair vs. Replacement at a Glance
| Treatment | Cost (per pane/window) | Lifespan Gain | Energy Boost | Best When… |
|---|---|---|---|---|
| Defogging | $75–$150 | 2–5 years | Moderate | You need a quick, budget-friendly fix |
| Resealing/Spacer Fix | $100–$200 | 3–7 years | Good | Seal failure is recent or minor |
| Partial Pane Replacement | $150–$300 | 7–12 years | Very Good | Panes are cracked or heavily fogged |
| Full Window Replacement | $300–$600 | 15–25 years | Excellent | Frames or seals are beyond repair |
4. Step-By-Step Defogging Walkthrough
- Inspect: Make sure that the haze is inside the panes, not on the surface.
- Drill: Carefully bore a tiny (2–3 mm) hole at the corner.
- Vacuum & Dry: Hook up your moisture-vacuum tool and pull out every drop of dampness.
- Seal: Fill the hole with clear epoxy and cap it neatly.
- Test: Wipe off any residue, then admire your crystal-clear view.
5. DIY Kit vs. Calling a Pro
- DIY Kits
- Pros: Super cheap ($30–$60), instant gratification.
- Cons: Limited desiccant, visible epoxy dot, no long-term warranty.
- Professional Service
- Pros: Heavy-duty desiccants, seamless finish, 1–10-year warranties.
- Cons: Higher upfront cost, you’ll need to book an appointment.
6. Your Quick FAQ
Is defogging a forever fix?
It’s more of a “keep you comfortable for years” fix—expect 2–5 years before moisture creeps back in.
Can every IGU be repaired?
If the frame’s warped or the glass is badly cracked, replacement is the safer bet.
Reseal or replace?
Minor, fresh seal failures lean toward resealing. Heavily damaged or repeatedly fogged units call for pane or full-window replacement.
Will repair really cut energy costs?
Yes—sealing restores that insulating air cushion, trimming 5–15% off your heating and cooling bills.
What warranties cover these fixes?
DIY kits usually come warranty-free. Pros offer anything from 1 to 10 years, depending on the method.
Next time you spot that misty layer between your window’s panes, you’ll know you’re just a few simple steps away from clear views, cozy drafts, and a happier wallet.
