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Window Repair Guide
Updated January 2024
12 min read

Foggy Windows Between Glass Panes? Complete Condensation Repair Guide

Don't let foggy windows ruin your home's appearance and energy efficiency. Learn the causes, DIY solutions, and when to call professionals for window condensation issues in Toronto.

Quick Action Required?

If you're dealing with extensive fogging or multiple failed windows, get a professional assessment.

Call (416) 555-1234 - Free Quote

Understanding Window Condensation Issues

Quick Diagnosis

Condensation ON the glass? Usually a humidity/ventilation issue.
Condensation BETWEEN glass panes? Seal failure - requires repair or replacement.

Window condensation between glass panes (also called "fogging" or "failed seals") affects over 60% of double-pane windows over 15 years old in Toronto's climate. The issue occurs when the seal between glass panes deteriorates, allowing moisture to enter the insulated space.

Why This Happens in Toronto

Temperature Extremes

-20°C to +35°C swings stress window seals

High Humidity

Lake Ontario moisture increases seal pressure

UV Exposure

Sun degrades sealant compounds over time

4 Main Causes of Window Condensation

Seal Failure

High Impact

Most common cause - the seal between glass panes has deteriorated, allowing moisture to enter

$300-800 to replace

Temperature Fluctuations

Medium Impact

Extreme temperature changes cause expansion/contraction, weakening seals over time

Preventable with maintenance

High Humidity

Low Impact

Excess moisture in the air increases pressure on window seals

$50-200 dehumidifier

Poor Installation

High Impact

Windows not properly installed allow air and moisture infiltration

$500-1500 reinstallation

DIY Repair Methods (Try These First)

Important Disclaimer

DIY methods provide temporary relief at best. For windows under warranty or expensive custom units, consult professionals first to avoid voiding coverage.

1

Assess the Damage

Determine if condensation is between panes or just on surfaces

Time Required:5 minutes
Difficulty:Easy
Tools Needed:None

Step-by-Step Instructions:

  1. 1Clean both sides of the window thoroughly with glass cleaner
  2. 2Check if fog/condensation remains after cleaning
  3. 3If condensation persists between glass panes, seal is likely failed
  4. 4Take photos to document the extent of fogging
2

Try the Hair Dryer Method

For minor fogging, heat can sometimes clear moisture temporarily

Time Required:10-15 minutes
Difficulty:Easy
Tools Needed:Hair dryer, Extension cord

Step-by-Step Instructions:

  1. 1Set hair dryer to warm (not hot) setting
  2. 2Hold 6-8 inches away from window
  3. 3Heat the foggy areas for 2-3 minutes
  4. 4Note: This is only temporary - seal still needs repair
3

Drill and Drain Method

Advanced DIY option - drill small holes to release moisture

Time Required:30-45 minutes
Difficulty:Hard
Tools Needed:1/8" drill bit, Silicone sealant, Cleaning supplies

Step-by-Step Instructions:

  1. 1⚠️ Warning: This can damage your window permanently
  2. 2Drill small hole at bottom corner of affected pane
  3. 3Allow moisture to drain out over 24-48 hours
  4. 4Seal hole with clear silicone when dry
  5. 5Success rate: 30-50%, may need professional replacement

Professional Repair Options

Professional repairs offer higher success rates and warranties. Here's what Toronto window specialists typically recommend:

Seal Replacement

Replace failed seals while keeping existing glass

Cost Range:
$200-400 per window
Time Required:
2-3 hours
Success Rate:
85-95%
Warranty:
2-5 years

Glass Unit Replacement

Replace the entire insulated glass unit (IGU)

Cost Range:
$300-600 per window
Time Required:
1-2 hours
Success Rate:
100%
Warranty:
10-20 years

Full Window Replacement

Replace entire window frame and glass

Cost Range:
$500-1200 per window
Time Required:
2-4 hours
Success Rate:
100%
Warranty:
Lifetime

Why Choose Professional Repair?

  • • Proper diagnosis prevents recurring issues
  • • Warranties protect your investment
  • • Professional tools ensure lasting repairs
  • • Often covered by home insurance (with receipt)

Preventing Future Condensation Issues

The best repair is prevention. These strategies can extend your windows' life by 5-10 years:

Keep humidity levels between 30-50% in your home
Ensure proper ventilation in bathrooms and kitchen
Clean window tracks and weep holes regularly
Avoid using space heaters directly near windows
Schedule annual window maintenance inspections
Replace weather stripping when worn
Consider storm windows in extreme climates

When to Call Professionals Immediately

Don't wait if you notice:

Condensation appears between glass panes (not just on surface)
Multiple windows showing same issue
Windows are less than 10 years old (may be under warranty)
You notice drafts coming from around the window
Energy bills have increased significantly
Ice forms between glass panes in winter
Professional assessment needed for insurance claims

Get Professional Help Today

Free assessment • Same-day service available • 10-year warranty on replacements

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