Can a Cracked Windscreen Cause an MOT Failure?
Yes, a cracked windscreen can definitely cause your vehicle to fail its Ministry of Transport (MOT) test. The MOT test is a critical annual inspection designed to ensure vehicles are safe and roadworthy, and the condition of the windscreen is a key component of this assessment. It's not just about the aesthetics of a crack; it's about visibility, structural integrity, and potential hazards it might present to the driver and other road users.
The rules regarding windscreen damage are detailed in the MOT test guidelines. These guidelines specify precisely where and how large a crack or chip can be before it becomes a failure point. The primary concern is ensuring the driver's view of the road is unobstructed and that the windscreen remains structurally sound, especially in case of an accident where it plays a role in supporting the roof structure.
- Cracked windscreens can fail MOT if damage impairs driver visibility.
- Damage within the driver's direct line of sight is a critical failure point.
- Windscreen integrity and structural soundness are assessed during the MOT.
- Specific dimensions and locations determine if a crack leads to failure.
For an MOT to be passed, the windscreen must meet stringent requirements set out by the Driver and Vehicle Standards Agency (DVSA). If your vehicle arrives for its test with a windscreen that breaches these regulations, the tester is obligated to fail it. This means you will need to have the windscreen repaired or replaced before the vehicle can be re-tested and legally driven.
The Driver's Direct Line of Sight Explained
The most common reason a cracked windscreen fails an MOT is that the damage obstructs the driver's view. The MOT test guidelines define the 'area swept by the windscreen wipers' as the critical zone. Within this zone, specifically in front of the driver's eyes, any damage that impairs visibility is unacceptable. This area is generally considered to be the section of the windscreen directly in the driver's field of vision. If a chip or crack extends into this area and is of a certain size, it will automatically result in a fail.
The DVSA's guidance specifies that any damage within this primary driving area that is larger than 10mm in diameter is a failure. Additionally, chips in the same area that are 10mm or more, but less than 40mm, if they are in the 'zone B' area (which is a smaller, more critical section within the primary driving area), will also lead to failure. This focus on the driver's direct line of sight underscores the paramount importance of clear visibility for road safety. An MOT tester will meticulously examine this area, looking for any imperfections that could compromise your ability to see hazards, traffic signals, or other road users.
MOT Test Guidelines for Windscreen Damage
The MOT test guidelines are very specific about what constitutes a fail concerning damaged windscreens. These rules are designed to be objective, ensuring consistency across all testing stations and testers. The primary considerations are the size, type, and location of the damage.
Types of Windscreen Damage Assessed
During an MOT, a tester will look for several types of damage to the windscreen:
- Chips: These are small imperfections where a piece of the glass has been dislodged.
- Cracks: These are fractures that run through the glass.
- Asterisk damage: This is a starburst-shaped crack, often caused by stone impact.
- Blotches: These are areas of discolouration or delamination within the glass.
The MOT test guidelines distinguish between chips and cracks, and their impact on visibility and structural integrity. A chip that is too large or too close to the driver's line of sight can be a failure. Similarly, a crack that extends into the critical viewing area or is excessively long will also result in a fail.
Specific Dimensions and Locations for Failure
The MOT testers use precise measurements and definitions to assess windscreen damage. The key areas are:
- Zone A (Driver's direct field of vision): This covers the area swept by the driver's wiper, directly in front of the driver. Any chip larger than 10mm or any crack within this zone will cause the vehicle to fail.
- Zone B (Passenger's direct field of vision): This is a larger area in front of the passenger seat. Chips larger than 40mm or cracks extending into this area can lead to a fail.
- Rest of the windscreen: Damage outside these critical zones might be acceptable if it does not obscure vision or compromise the windscreen's structural integrity. However, multiple smaller chips or cracks, even if outside the primary zones, could still lead to an advisory notice or a fail if they collectively obscure vision or weaken the glass significantly.
The MOT test guidelines also state that any damage that causes the windscreen to be shattered or significantly weakened is an automatic fail. This includes cracks that spread across a large portion of the glass or multiple large chips that compromise the windscreen's ability to provide structural support to the vehicle's roof in the event of a rollover.
Check your windscreen for any visible damage before your MOT appointment. Even small chips can spread, especially with temperature changes or vibrations, turning a minor issue into a fail.
Structural Integrity Considerations
Beyond visibility, the MOT test considers the structural role of the windscreen. Modern windscreens are bonded in place and contribute significantly to the car's chassis rigidity, particularly supporting the roof in a rollover. If a crack is so severe that it compromises this structural integrity, even if it's not directly in the driver's line of sight, it can be deemed a safety defect and lead to a fail. The tester will be looking for signs that the glass is delaminating, has lost its lamination, or is severely compromised by extensive cracking.
What to Do If Your Windscreen Damage Might Cause an MOT Fail
If you suspect your cracked windscreen might lead to an MOT failure, the best course of action is proactive repair or replacement. Waiting until the test itself, only to discover it's a fail, means you'll have to book a re-test after the necessary work is done, incurring extra costs and delays. Addressing the issue beforehand can save time and potential frustration.
Repair vs. Replacement: When to Choose Which
The decision between repairing a chip or replacing the entire windscreen often depends on the extent and location of the damage, as well as the specific MOT guidelines. Many minor chips, especially those outside the driver's direct line of sight, can be repaired relatively quickly and affordably. Specialist windscreen repair services can often fill chips, preventing them from spreading and restoring the glass's structural integrity.
However, if the damage is a crack, or if a chip is too large or too close to the edge of the windscreen, repair may not be possible or advisable. Cracks that are longer than a few centimetres, or any damage within the driver's direct line of sight (Zone A as defined by MOT guidelines), generally require a full windscreen replacement. A replacement ensures that the new windscreen meets all safety and visibility standards required for an MOT pass.
The most proactive approach to ensure your vehicle passes its MOT is to address any windscreen damage well in advance of the test date.
Finding a Reputable Windscreen Service
When seeking a repair or replacement, it's crucial to choose a reputable service. Look for technicians who are experienced with MOT requirements and use quality materials. Many national chains and local garages offer windscreen services. You can often get a quote and book an appointment online or by phone.
When you contact a service, be prepared to describe the damage: its size, type (chip or crack), and location on the windscreen. They will advise whether a repair is feasible or if a replacement is necessary. If you're approaching your MOT, inform them of this; they can often prioritise urgent repairs to help you get your vehicle roadworthy in time.
Checking When Your MOT is Due
Knowing when your MOT is due is vital for managing vehicle maintenance. You can easily check when your MOT is due online using your vehicle's registration number on the official government website. This allows you to plan any necessary repairs, including windscreen work, well in advance.
If you discover your MOT is due soon and you have windscreen damage, it's wise to get it assessed immediately. This way, you have ample time to arrange for repairs or replacement, ensuring you don't face an MOT failure and the subsequent need for a re-test. Remember, you can usually book an MOT up to a month before your current one expires without losing any of the time from your existing certificate.
Always ask for a windscreen that meets or exceeds the original manufacturer's specifications for your vehicle. This ensures optimal fit, visibility, and safety compliance, which is paramount for passing your MOT.
What Happens If Your Car Fails the MOT Due to Windscreen Damage?
Discovering that your vehicle has failed its MOT, particularly due to a cracked windscreen, can be frustrating. However, understanding the process that follows can help you navigate the situation effectively and get back on the road legally as soon as possible.
The MOT Test Certificate and Failure Notice
Upon completing the MOT test, the tester will issue a certificate. If your vehicle passes, it will receive a VT20 pass certificate. If it fails, you will receive a VT30 advisory notice, which details the reasons for the failure. This notice will clearly list the windscreen damage as a reason for the failure, often citing the specific guideline that has been breached (e.g., damage obstructing the driver's direct line of sight).
It is important to note that once your vehicle fails its MOT, it is generally not legal to drive it on public roads unless you are driving it to a pre-booked MOT re-test or to a place of repair. Driving a vehicle with an expired MOT certificate or one that has failed is a serious offence and can lead to fines and penalty points.
Getting the Windscreen Repaired or Replaced
The immediate next step after failing your MOT due to a cracked windscreen is to arrange for the repair or replacement of the glass. You can take your car to any reputable garage or specialist windscreen repair company. As discussed previously, the nature and extent of the damage will determine whether a repair is sufficient or if a full replacement is necessary.
When booking the repair, inform the service provider that the work is needed to rectify an MOT failure. They will ensure the work is carried out to the required standards. For a repair to be valid for a re-test, it must fully address the reason for the failure. If the windscreen is replaced, the new unit must be fitted correctly and meet all relevant safety standards.
The MOT Re-test Process
Once the windscreen has been repaired or replaced, your vehicle will need to undergo an MOT re-test. The rules for re-tests can vary slightly depending on where you get the work done and whether you are within a specific timeframe.
If you leave your car at the original test centre for repair and it is repaired on-site, then a partial re-test may be offered, which is usually free of charge if completed within one working day of the initial failure. This re-test will focus only on the items that failed. However, if you take your car away for repair and then bring it back to the same test centre within a specific period (typically up to 10 working days), a partial re-test focusing on the failed items will still apply.
If you take your vehicle elsewhere for repairs, or if more than 10 working days pass before it is presented for re-test, you will likely have to pay for a full MOT test again. To avoid this, it is advisable to arrange for repairs promptly and book the re-test as soon as possible after the work is completed. A successful re-test will result in a new VT20 pass certificate being issued, making your vehicle legal to drive on the road.
Can You Tax a Car Without an MOT?
You cannot tax a car without a valid MOT certificate. The requirement for a valid MOT is a prerequisite for vehicle tax renewal in the UK. If your car fails its MOT and you have not yet had the failure rectified and passed a re-test, you will not be able to renew your vehicle tax. This further emphasises the importance of addressing any MOT failure issues promptly to ensure your vehicle remains road legal.
The system automatically checks for a valid MOT record before allowing you to tax your vehicle. Therefore, once your car has passed its re-test and a new MOT certificate is issued, you can then proceed with taxing your vehicle as usual. If you are unsure about when your MOT is due, or if you have recently had repairs done, you can check your MOT status online using your vehicle's registration number.
Windscreen Chips vs. Cracks: The MOT Distinction
When it comes to MOT failure related to windscreens, the distinction between a chip and a crack is significant. While both can lead to a fail, the MOT test guidelines apply different criteria based on the nature of the damage. Understanding this difference can help you assess the risk and decide on the appropriate action.
What Constitutes a Chip in MOT Terms?
A chip is defined as a small area of damage where the glass has been dislodged, typically caused by impact from stones or debris. For MOT purposes, the size and location of a chip are paramount. A chip smaller than 10mm in diameter, located outside the driver's direct line of sight (Zone A), might be acceptable. However, if a chip is 10mm or larger, or if it falls within Zone A, it will result in an MOT failure. Even if a chip is outside Zone A but is larger than 40mm, it can also cause a fail.
Often, a single chip can be repaired, especially if it's minor and not in a critical area. Windscreen repair involves injecting a special resin into the damaged area, which hardens and bonds the glass, preventing the chip from spreading and restoring clarity. If the chip is within the permissible limits, a repair can rectify the issue, ensuring your car passes the MOT.
What Constitutes a Crack in MOT Terms?
A crack is a fracture that extends through the glass. Unlike a chip, a crack typically has a length rather than just a diameter. The MOT guidelines are particularly stringent regarding cracks because they can compromise the structural integrity of the entire windscreen and significantly impair visibility over a larger area.
Any crack that is within the area swept by the windscreen wipers (Zone A) is an automatic failure. Furthermore, cracks that extend more than 40mm into the windscreen's surface, even if outside Zone A, can also lead to a fail. The MOT tester will examine the length and direction of the crack to determine if it affects the driver's view or the windscreen's structural soundness. Because cracks are more likely to spread and compromise the entire windscreen, they are often considered more serious than chips.
The Impact of Damage Location
The location of both chips and cracks is a critical factor in the MOT test. As mentioned, the area directly in front of the driver (Zone A) is the most sensitive. Damage here, whether a chip or a crack, is almost certain to cause a fail. This is because any obstruction in the driver's primary field of vision poses an immediate safety risk.
The MOT test guidelines also consider Zone B, which is the area swept by the passenger-side wiper. While slightly less critical than Zone A, damage here still matters. Chips of 10-40mm in Zone B or cracks extending into this zone can lead to failure. Damage outside these zones is less likely to cause a failure unless it is extensive, compromises the structural integrity of the windscreen, or causes significant reflection or distortion that affects the driver's view.
How to Check Your MOT Status
If you are concerned about your windscreen's condition or want to know when your MOT is due, you can check your vehicle's MOT status online. The government provides a free service where you can enter your vehicle's registration number to see its MOT expiry date and check its previous MOT history, including any advisories or failures.
This tool is invaluable for car owners. It allows you to stay on top of your vehicle's legal requirements and plan maintenance. If you check your MOT status and see that your expiry date is approaching, and you know you have windscreen damage, you can take proactive steps to get it assessed and repaired before the test date, thus avoiding the inconvenience and cost of a failure.
Understanding Windscreen Damage Advisories
Not all windscreen damage results in an immediate MOT failure. Sometimes, a tester might issue an advisory notice for damage that, while not currently failing the vehicle, could become a problem in the future. Understanding these advisories is crucial for proactive vehicle maintenance and avoiding future MOT failures.
What is an MOT Advisory?
An MOT advisory notice is given when a vehicle has a defect that is not serious enough to cause an immediate failure but may become more serious in the future. These advisories are recorded on the MOT certificate and can alert the driver to potential issues that should be addressed. It's important to treat advisories seriously, as they are essentially warnings of potential future problems.
Windscreen Damage as an Advisory
A common reason for a windscreen advisory is minor damage that is not within the driver's direct line of sight and does not exceed certain size limits. For example, a chip outside Zone A, or a crack that is very short and does not affect visibility, might be logged as an advisory. The tester may note the size and location of the damage, suggesting that it should be monitored.
An advisory for windscreen damage might state something along the lines of: 'Nearside/Offside windscreen chip/crack exceeding 10mm but not in Zone A'. This indicates that the damage is present and noted, but it doesn't currently breach the MOT failure criteria. However, the tester is flagging it because such damage has a tendency to spread, especially with changes in temperature or vibrations from driving.
Why You Should Act on Advisories
While a vehicle with a windscreen advisory can still pass its MOT, ignoring it is a false economy. The primary reason is that chips and cracks can and often do spread. A small chip that was deemed acceptable could, over weeks or months, develop into a long crack that breaches the MOT failure criteria. If this happens, your vehicle will fail its next MOT, and you will have to pay for either a repair or a replacement before it can be re-tested.
Acting on an advisory promptly can save you money and hassle in the long run. If the damage is minor, a repair is often relatively inexpensive and can prevent the need for a costly windscreen replacement. Even if the damage is not yet in the driver's direct line of sight, a repair can stop it from spreading into that critical area, thus avoiding a future failure.
If your car receives an MOT advisory for windscreen damage, get a quote for repair immediately. Many insurance policies include windscreen cover, which might cover repairs or replacements at no extra cost to you.
The Role of the DVSA
The Driver and Vehicle Standards Agency (DVSA) sets the MOT test guidelines. These guidelines are regularly updated to reflect changes in vehicle technology and safety standards. The DVSA's aim is to ensure that all vehicles on the road are safe. Their inspectors ensure that MOT test centres and testers adhere to these strict rules. For windscreens, the focus remains firmly on ensuring clear visibility and structural integrity for the driver and all occupants.
If you have any doubts about your windscreen's condition, it's always best to consult with an MOT test centre or a professional windscreen repair specialist. They can provide an expert opinion on whether the damage is likely to cause a fail or if it warrants an advisory, and what steps you should take.
How to Check When MOT is Due and Other MOT FAQs
Knowing when your MOT is due and understanding the broader implications of MOT compliance are essential for any car owner. A proactive approach to your vehicle's MOT status ensures you remain legal on the road and avoid unexpected costs or penalties. Here, we address common queries related to MOT testing and windscreen condition.
How Can You Check When MOT is Due?
Checking when your MOT is due is a straightforward process that can be done online. The UK government provides a free, official service where you can enter your vehicle's registration number to find out its MOT expiry date. This service also allows you to view your vehicle's previous MOT test results, including any advisories or failures.
You can access this service via the 'Check your vehicle's MOT status' page on the GOV.UK website. It is advisable to check your MOT status periodically, especially if you have recently purchased a used car or if your MOT is approaching. This allows you to schedule any necessary maintenance or repairs in advance, rather than leaving it to the last minute.
How Much Does it Cost for MOT?
The maximum fee that an MOT test centre can charge is set by the government. For cars, the maximum fee is £54.85. This fee applies to a standard MOT test. For some larger vehicles, such as Class 7 goods vehicles, the maximum fee is higher. It's important to note that this is the maximum fee; many test centres may charge less.
If your vehicle fails its MOT, the cost of a re-test can vary. If you leave your vehicle at the test centre for repairs and it is re-tested within one working day, the re-test is usually free. If you collect your vehicle and bring it back for a re-test within 10 working days, a partial re-test may be charged at a lower rate. If more than 10 working days pass, or if you use a different test centre, you may have to pay for a full MOT test again. Always clarify the re-test policy and costs with your chosen test centre when booking your initial MOT.
How to Check MOT
Checking your MOT status, as mentioned, is best done online via the GOV.UK website using your registration number. This will show you if your vehicle has a valid MOT certificate and when it expires. If you are preparing for an MOT test, you can perform a basic check yourself. Look for obvious issues such as worn tyres, non-functioning lights, or any significant damage to the windscreen that might fall within the failure criteria discussed earlier.
Will a Cracked Windscreen Fail MOT?
In summary, a cracked windscreen will fail an MOT if the damage is within the driver's direct line of sight (Zone A) and is larger than 10mm, or if it is a crack extending over 40mm into the windscreen. Damage in other areas may also lead to failure if it significantly impairs overall visibility or compromises the structural integrity of the windscreen. Always check the specific DVSA guidelines or consult with an MOT centre if you have any doubts.