When that dreaded sound of a stone hitting your windscreen happens, the questions start immediately: Can this be repaired? Do I need a complete replacement? Will my insurance cover it? At My Car Glass, with over 30 years of experience serving London's drivers, we've seen every type of windscreen damage imaginable - and we've created this definitive guide to help you make the right decision.
The 30-Second Assessment: Is Your Damage Repairable?
Before diving into the details, here's a quick way to assess your situation:
LIKELY REPAIRABLE if ALL of these are true:
Chip smaller than a £2 coin (under 25mm)
Located more than 3cm from any edge
Not directly in driver's line of sight OR smaller than 10mm if it is
Only affects the outer layer of glass
No more than 3 chips on the entire windscreen
LIKELY NEEDS REPLACEMENT if ANY of these are true:
Crack longer than your credit card (85mm)
Damage at or within 3cm of windscreen edge
Larger than 10mm in driver's direct field of vision
Inner layer of glass is damaged
Multiple chips or complex crack patterns
QUICK ACTION TIP: Take a clear photo of the damage next to a coin for size reference. This helps our technicians provide accurate advice before your appointment.
Understanding Different Types of Windscreen Damage
Not all windscreen damage is created equal. The repair potential often depends on the specific type of damage:
Repairable Damage Types
Bull's Eye: Circular chip with a cone in the outer layer (high repair success)
Star Break: Short cracks extending from a central impact point (usually repairable if contained)
Combination Break: Bull's eye with short radiating cracks (repairable if under 25mm total)
Single Crack: Straight-line crack (potentially repairable if under 75mm and not near edges)
Damage Usually Requiring Replacement
Edge Crack: Any crack that reaches or starts within 3cm of the windscreen edge
Floater Crack: Long crack not connected to an edge (if over: 75mm)
Multiple Cracks: Intersecting cracks or complex patterns
Deep Impact Damage: When both layers of laminated glass are compromised
DID YOU KNOW? According to Highways England, a windscreen chip is 7 times more likely to spread into a crack during cold weather. London's temperature fluctuations make prompt repairs especially important.
The Science Behind Windscreen Damage
Understanding why some damage can be repaired while other types can't requires understanding how your windscreen is constructed:
Modern windscreens are actually sandwich structures - two layers of glass with a plastic interlayer (typically PVB - polyvinyl butyral) between them. This design is crucial for safety, as it:
Prevents glass from shattering into dangerous shards during accidents
Maintains structural integrity even when cracked
Contributes significantly to your vehicle's overall structural strength
When a stone hits your windscreen, it typically damages only the outer layer of glass. The repair process works by injecting specialized resin into this damaged area, which:
Fills the void created by the impact
Bonds with the surrounding glass
Restores approximately 90-95% of the structural integrity
Improves optical clarity in the damaged area
EXPERT INSIGHT: According to BRAKE Road Safety Charity, windscreens contribute up to 30% of a vehicle's structural strength in a rollover accident, making proper repairs crucial for safety.
Location Matters: The Windscreen Danger Zones
The location of damage is often more important than size when determining repairability:
Zone A (Driver's Line of Sight)
This critical area directly in front of the driver (approximately 290mm wide centred on the steering wheel) has the strictest requirements:
Damage must be smaller than 10mm to be repairable
Even tiny imperfections can create dangerous light refraction or distortion
MOT tests specifically check for damage in this area
Edge Zone (Within 3cm of any edge)
Damage near edges is particularly problematic because:
The windscreen edges experience the most stress during driving
Edge damage compromises the structural frame connection
Repairs in this area have a much higher failure rate
Small edge chips often spread rapidly into large cracks
Middle Zone
The central area of your windscreen (excluding the driver's direct line of sight):
Can tolerate larger repairs (up to 25mm)
Has the highest repair success rate
Less likely to spread quickly than edge damage
LEGAL CHECK: The DVSA MOT inspection manual states that windscreen damage larger than 10mm in Zone A will result in an automatic MOT failure.
Cost Comparison: Repair vs. Replace
Repair Costs
Our standard chip repair price: £69.99 + VAT
With insurance: Typically £10-20 (customer pays excess)
Average repair time: 30-45 minutes
Insurance note: While windscreen claims used to be completely free, most insurers now charge a small excess
Be aware: Though less common, windscreen claims can potentially affect your no claims bonus with some insurers
Replacement Costs
Basic vehicles: £200-£350 (depending on make/model)
Luxury or vehicles with ADAS: £350-£1,000+
Average time: 1-2 hours (plus curing time)
Insurance typically has an excess payment (£60-£150)
Some insurers waive excess if you use their preferred supplier
The Cost of Delay
One of the most expensive mistakes London drivers make is delaying windscreen repairs:
Small chips can spread rapidly in winter due to temperature changes
London's busy roads mean more vibration, causing cracks to spread faster
ADAS recalibration costs (when eventually needed) can add £150-£300
Insurance Claims Made Easy
Typical Coverage Options
Comprehensive policies: Usually include windscreen cover
Third-party, fire and theft: Typically doesn't include windscreen coverage
Windscreen add-on: Available for approximately £30-£50 annually
Will a Claim Affect Your Premium?
While windscreen claims are treated differently than other claims, policies have changed in recent years:
Some insurers may impact your No Claims Bonus (check your specific policy)
Most have a small excess (typically £10-20) rather than being completely free
Multiple windscreen claims within a short period will likely trigger a review of your policy
Some insurers still offer dedicated windscreen coverage that won't affect your main policy
CONSUMER ADVICE: The Money Helper service provides independent guidance on insurance policies and claims processes to help you understand your coverage options.
When DIY is DON'T: The Risks of Home Repair Kits
While DIY windscreen repair kits (typically £10-£20) might seem tempting, they come with significant risks:
Limited effectiveness on anything but the simplest chips
No professional equipment to create proper vacuum conditions
Lower quality resins that yellow and shrink over time
Risk of making damage worse and necessitating full replacement
Potential to void insurance coverage for future damage
No guarantee or warranty protection
CASE STUDY: A recent AA survey found that 76% of DIY windscreen repairs required professional intervention within 6 months, ultimately costing consumers more than if they'd chosen professional repair initially.
The My Car Glass Advantage
At My Car Glass, we work directly with all major insurers to:
Provide direct billing services (no upfront payment needed)
Handle all paperwork and approval processes
Maximize your coverage benefits
Ensure you receive OEM-quality glass even when using insurance
REAL CUSTOMER EXPERIENCE: "When my windscreen cracked on the M25, I was worried about the cost and hassle. My Car Glass handled my insurance claim directly and had me back on the road within hours. The entire process was effortless." - Sarah T., London
ADAS Considerations: Modern Windscreens Need Specialized Care
If your vehicle has Advanced Driver Assistance Systems (ADAS) such as:
Lane departure warning
Automatic emergency braking
Adaptive cruise control
Rain-sensing wipers
Heads-up display
Then your windscreen replacement and repair needs are more complex:
Cameras and sensors mounted on or behind the windscreen must be recalibrated
Improper calibration can lead to safety system malfunctions
Not all repair shops have the necessary calibration equipment
My Car Glass has invested in factory-level calibration technology for all major vehicle brands
SAFETY ALERT: Thatcham Research warns that uncalibrated ADAS systems after windscreen replacement can lead to safety systems failing when needed most.
Seasonal Windscreen Care: London Weather Considerations
London's unique climate creates specific challenges for windscreen maintenance:
Winter Considerations
Small chips are 60% more likely to spread in freezing temperatures
Never pour hot water on a frozen windscreen with existing damage
Use a proper ice scraper, not metal objects that can scratch glass
Allow extra time for proper defrosting to avoid thermal stress
Summer Considerations
Park in shade when possible to prevent extreme heat on damaged areas
Address small chips before summer heat waves
Use windscreen sun shields when parked for extended periods
Be cautious with air conditioning settings to avoid thermal shock
LOCAL TIP: London's temperature can vary by up to 8°C between central areas and outskirts. This temperature differential, especially during commutes, can stress damaged windscreens. Met Office data shows this urban heat island effect is most pronounced from May to September.
The My Car Glass Windscreen Assessment Process
When you call My Car Glass about windscreen damage, we follow a comprehensive assessment process:
Photo Analysis: We'll ask you to send photos of the damage for preliminary assessment
Size Measurement: We use precise digital measuring tools to determine exact dimensions
Location Mapping: We assess the position relative to critical areas and edges
Stress Evaluation: We check for signs of spreading or stress patterns
Glass Type Identification: We determine if your vehicle has specialized glass (acoustic, heated, etc.)
ADAS Verification: We check if calibration will be required
Insurance Check: We verify your coverage and excess details
Recommendation: We provide our professional assessment on repair vs. replacement
When to Act Immediately: Emergency Situations
Some windscreen damage situations require immediate attention:
Cracks that obstruct driver visibility
Damage that's actively spreading (you can often hear it "clicking" as it expands)
Impact damage that has penetrated both layers of glass
Damage that coincides with water leakage
Any damage that creates sharp edges or glass particles inside the vehicle
In these cases, My Car Glass offers emergency same-day service throughout London and surrounding areas.
Customer Success Stories
Fleet Manager Testimonial: "Managing a fleet of 45 delivery vehicles across London, windscreen damage is a constant challenge. Since partnering with My Car Glass three years ago, we've reduced our windscreen replacement costs by 32% through their proactive repair approach. Their mobile service means minimal vehicle downtime." - James H., Operations Manager
Family Vehicle Experience: "When my Range Rover's windscreen cracked with all the advanced driving systems, I was worried about getting everything calibrated correctly. My Car Glass handled everything perfectly, explaining each step and ensuring all the safety features worked properly afterward." - Michelle K., Kensington
Classic Car Specialist Review: "Finding someone who understands the specific needs of vintage vehicles isn't easy. My Car Glass sourced the correct specification glass for my 1968 Jaguar E-Type and installed it with meticulous attention to detail. Exceptional service." - Richard B., Kingston
Frequently Asked Questions
Q: How long does a windscreen repair take? A: Most standard repairs take 30-45 minutes to complete. The resin curing time is included in this estimate.
Q: Can I drive immediately after a windscreen repair? A: Yes, you can drive immediately after the repair is completed. The resin cures fully during the repair process.
Q: Will my insurance cover windscreen repair or replacement? A: Most comprehensive policies include windscreen coverage, often with a lower or zero excess for repairs compared to replacements. We can check your specific policy details.
Q: How long should I wait to wash my car after windscreen replacement? A: We recommend waiting 24-48 hours before using a car wash or applying significant water pressure to a newly replaced windscreen.
Q: Can a cracked windscreen be repaired rather than replaced? A: Small cracks (under 75mm) that aren't in the driver's line of sight and are away from edges can sometimes be repaired. Longer cracks typically require replacement.
Q: Does My Car Glass provide mobile service? A: Yes, we provide mobile service throughout London and surrounding areas at no additional charge.
Conclusion: The My Car Glass Difference
With over three decades of experience serving London and surrounding drivers, My Car Glass brings unmatched expertise to every windscreen assessment. Whether your windscreen needs a precision repair or complete replacement, you'll benefit from:
Technicians with an average of 15+ years of experience
OEM-quality materials for all repairs and replacements
The latest diagnostic and repair technology
Comprehensive insurance knowledge and direct billing
Mobile service throughout London at no additional charge
Lifetime warranty on all workmanship
Don't take chances with questionable repairs or inexperienced technicians. Contact My Car Glass today at 020-8909-2300 for a free, expert assessment of your windscreen damage.