The replacement of windshields in modern cars is subject to clearly higher requirements than in previous decades.

Today, the windshield is part of the car’s load-bearing body structure, and its impact on safety is significant.

In addition, windshields today have cameras and other sensors that affect the active safety of the car.

The safest way to remove the windshield from the frame is nylon thread, which does not damage the paintwork or upholstery.

Before installing new glass, the frame opening is thoroughly cleaned and any rust damage is repaired. Photo: Pekka Virtanen

In 2019, more than 160,000 glass damage occurred in Finland.

In addition to car repair shops that carry out body repairs, companies specializing in windscreen work also make significant glass changes.

Calibration of cameras and adjustment of sensors requires large equipment investments, so the majority of windshield repair shops have to subcontract work to a branded repair shop or a multi-brand or body repair shop where the necessary equipment can be found. Photo: Pekka Virtanen

Since 2007, the Confederation of Finnish Automotive Industries (AKL) has developed a quality classification for body repair shops, the aim of which is to ensure the technical and operational ability of body repair shops to provide customer-oriented, high-quality and cost-effective service.

Alongside the three-level rating, AKL launched a new windshield rating at the end of last year, which aims to provide even higher-quality repairs in glass damage as well.

The aim of the TL classification is to ensure that in the future, windscreen and maintenance workshops working on windscreens will also have sufficient tools and expertise to repair and replace vehicle windows.

Careful application of adhesive and glue fire ensures good attachment of the windshield to the basket. Photo: Pekka Virtanen

The windshield was once a rain and sleet shelter, but today, as part of the car’s load-bearing structure, it acts as a occupant safety in the event of a crash.

In addition, cameras attached to the windshield nowadays, after replacing the windshield, virtually always require alignment to function properly.

- New cars are increasingly equipped with new materials - if, for example, the windscreen is incorrectly removed from the carbon fiber body, it can cause great damage and a big drop for the workshop.

It must be remembered that new windshields do not leak, but the cause of leaks and hisses can always be found in the attachment between the glass and the body, reminds Tomasz Salamon, technical expert at Saint-Gobain Autover Finland Oy.

Mika Salmi, the maintenance manager of the body repair shop in Veho Suutarila, which replaces hundreds of windshields every year, emphasizes the same thing:

- The biggest mistakes are usually made during the gluing stage, when the glass is left to leak from one of the edges or to rustle while driving.

The adhesive bead is a seal between the windscreen and the car body, so there must be no gaps or discontinuities in the adhesive bead through which water enters the car's structures.

The glue used determines the drying time, and we try to keep the car in place during the drying time.

Another big mistake is that the cameras on the windshield are not calibrated and the sensors are not adapted to the new windshield.


 If the rain or twilight sensor is not notified of the new windshield, the systems it controls may not work in the same way as before replacing the windshield.

- The car may not report a fault on an uncalibrated camera, but, for example, the high beam automation may malfunction and onlookers will be dazzled.

If the rain or twilight sensor is not told about the new windshield, the systems it controls may not work in the same way as before replacing the windshield, says Mika Salmi.

Calibration of the windshield camera or cameras is also required if the car chassis is raised or lowered.

Usually, the rain and twilight sensor under the same “eye” is set to a certain brightness of the glass, and if the color of the glass changes - this is also the case when using car manufacturer’s original glass - the windscreen wipers and automatic lighting do not work as before.

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When transporting a modern car for windshield replacement, it must therefore be ensured that the replacement work also includes the calibration of the cameras and the adjustment of the sensors.

Most windshield repair shops will have to subcontract these works, but this phase of work should not incur any additional costs for the customer.