Troubleshooting & Repairs

Module 5: Troubleshooting & Repairs 

1. Advanced Defect Diagnosis & Remediation

Condensation in Insulated Glass Units (IGUs):

• Root Causes:

• Desiccant saturation (typically after 10-15 years)

• Seal failure (primary or secondary seal degradation)

• Thermal bridging from aluminum spacers (pre-2010 units)

• Diagnostic Methods:

• Infrared thermography to identify thermal breaks

• Gas analysis (argon concentration <80% indicates leakage)

• Repair Solutions:

• Full IGU replacement with warm-edge spacers (stainless steel or thermoplastic)

• Temporary mitigation using perimeter silicone sealant (3-year lifespan)

Structural Sealant Failure:

• Failure Modes:

1. Adhesive failure (sealant detaches from substrate)

2. Cohesive failure (internal tearing of sealant)

3. UV degradation (surface cracking)

• Testing Protocols:

1. Peel adhesion test (ASTM D903)

2. Shore A hardness measurement (deviation >15% indicates aging)

• Replacement Procedure:

1. Complete removal of failed sealant (mechanical + solvent cleaning)

2. Surface priming with approved adhesion promoter

3. New silicone application (minimum 6mm width:depth ratio)

Glass Stress Fractures:

• Fracture Pattern Analysis:

• Radial cracks from point impact (typical of mechanical damage)

• Nickel sulfide (NiS) inclusions causing spontaneous breakage

• Preventative Measures:

• Heat soak testing (EN 14179-1) for tempered glass

• Edge polishing to remove micro-fractures

• Emergency Containment:

• Structural film application (2mm PET) for temporary stabilization

2. Retrofit Solutions for Energy Efficiency

Glazing Upgrade Pathways:

• Single to Double Glazing Conversion:

• Slim-profile IGUs (14mm overall) for existing frames

• Thermal spacer bars to prevent condensation

• Low-E Coating Retrofit:

• Magnetron sputter-coated films (U-value improvement from 5.6 to 1.8 W/m²K)

• Internal application options for heritage buildings

Frame Rehabilitation Techniques:

• Thermal Break Installation:

• Polyamide strip insertion in aluminum frames

• Reduces U-factor by 60%

• Air Tightness Improvements:

• Compression gasket replacement (EPDM to silicone)

• Aerogel insulation for frame cavities

Advanced Retrofit Systems:

• Secondary Glazing Solutions:

• Magnetic-mounted acrylic panels (3mm, 85% light transmission)

• Slide-and-fold systems with 32dB noise reduction

• Dynamic Glazing Overlays:

• Electrochromic films with 35-70% variable tint

• 0.5W/m² power consumption per m²

Repair Material Specifications

Case Study: Historic Window Retrofit

• Challenge: 19th-century steel windows with 6.2 W/m²K U-value

• Solution:

1. Ultrasonic cleaning of original frames

2. Vacuum-insulated glazing (4mm overall thickness)

3. Micro-probe thermal break installation

• Result: U-value reduced to 1.3 W/m²K with 95% original appearance retention

This module provides systematic methodologies for diagnosing glazing failures and executing compliant retrofits.