Right and Wrong Ways to Replace a Windshield

A vehicle’s windshield is a very important design component, as it not only protects the driver but also provides structural support for the vehicle. The windshield performs three important functions in the event of an accident:

  • The windshield keeps the passengers from being thrown out of the vehicle, even if they don’t wear a seatbelt. If the occupant is thrown from the vehicle, then he or she is at risk of the car rolling over them as well as sustaining severe impact-related injuries. Did you know that 75% of those thrown out of the vehicle do not survive the accident?
  • The windshield provides reinforcement for airbag deployment and acts as a barrier between the airbag and the outside of the car. If an improperly installed windshield pops out during an accident, the airbag is no longer inside the car, where it should be in order to protect the driver and front-seat passenger. Instead, the airbag ends up on the outside of the car, where it is useless.
  • The windshield provides up to 60% of the roof crush protection so that the roof of the vehicle does not collapse in a roll-over accident. If the windshield falls out in the event of a rollover accident, the roof of the vehicle can collapse. This situation can be much more deadly for occupants of the vehicle because it makes head trauma more likely.

Windshield replacement checklist

What are main elements to a quality windshield replacement? There are four:

  1. a professional certified technician,
  2. the right adhesive,
  3. the right glass,
  4. a warranty.

Read on to learn why.

What should you remember when consulting a technician regarding a windshield replacement? The first question you should ask the technician is whether he or she is a certified windshield replacement technician. If the answer is no, the first question should also be the last one you ask this technician. Certified technicians have been properly trained on the correct methods for installing windshields, and a properly installed windshield can save your life in case of an accident. You really don’t want to be driving in a vehicle that has a major safety hazard, can put you in the life-threatening danger, and will cost a lot of money in the long run.

Be sure to do some due diligence, and choose a well-established auto glass shop that values your safety, and does not cut corners to save a few dollars. Educate yourself. Don’t be shy to ask questions. Here are some questions you may want to ask:

  • are shop’s technicians NGA / AGRSS certified?

    Why is this important? NGA certification has been a gold standard in the industry for over 20 years, and it’s a benchmark for ensuring a properly installed windshield. In 2011, NGA has sold its certification program to Automotive Glass Replacement Safety Standards (AGRSS®) Council. The certification ensures that technicians have the right skills to do the job, up to date on industry safety standards, and trained on proper installation practices and procedures. In order for the windshield installation to be successful, it should comply 100% with manufacturer standards. When standards are not followed precisely, this can lead to an unsafe windshield installation which puts the customer at risk in the event of a collision. A less serious, but highly annoying, consequence of an improper installation might be excessive noise when driving at higher speeds. The car maker specifications include things like the size, shape, and thickness of the windshield itself, but also relates to installation techniques. View a copy of the Automotive Glass Replacement Safety Standard.
  • does the shop use urethane adhesive recommended by manufacturers? are the technicians trained on a proper use and application of urethanes?

    Why is this important? One of the most dangerous mistakes that is commonly made in windshield replacements is using the wrong type of adhesive. Materials like bathtub caulking or silicone should never be used. Butyl, a common sealant, is often used instead of urethane as a cost-cutting measure. Butyl tape is an inferior adhesive as it only holds 60lb per square inch. It does not have much strength and just pulls apart in case of an accident. If a shop uses Butyl because it is much cheaper – beware and avoid. Find an auto-glass shop that uses Urethane, a high-quality adhesive that holds 600lb per square inch, and will ensure your safety. If you asked the first question and your shop is AGRSS certified, it’s highly unlikely they will be using butyl. AGRSS requires shops to use polyurethane sealants for vehicles licensed for highway use, even if OEM installation used butyl. This can happen in case of some older vehicles that were manufactured when butyl was widely used as sealant.
  • does the shop offer a warranty?

    Why is this important? Even if the shop is certified, things could go wrong. If the windshield leaks (either water or air), you want to be sure the shop will stand behind their work and fix the problem.
  • what kind of glass does the shop use?

    Why is this important? There is a difference in quality between OEM and aftermarket windshields. OEM suppliers have strict quality controls and you can expect that replacement will be exactly same as the original one. Aftermarket products don’t follow the same quality standards, so it could happen that you’ll end up having some problems after replacement – bad fitment, noise, or air/water leakage. To be on a safe side, make sure the glass shop uses DOT-certified glass.
  • how long before the car can be driven?

    Why is this important? The adhesive used for windshield replacement needs to cure properly before the car is driving, or the seal between the windshield and car could be weak in some areas. The time will depend on the type of the adhesive used to install the windshield and can range from 3 to 24 hours. There are also some fast-cure adhesives that have one-hour drive-away time. It’s extremely important that you follow safe drive-away time recommended by adhesive manufacturer, so check with technician replacing your windshield about the recommended cure time for the type of urethane being used.
  • do the technicians go over the “do’s and don’ts” of post-installation usage with customers?

    Why is this important? Once the windshield is installed, there are a few things you should do not to ruin the results of replacement work. For example, you want to wait with washing your car for at least 24 hours so that you don’t damage seals. You want to keep at least one window open (an inch will do) to avoid building pressure inside of the vehicle because it could blow a hole in the seal, resulting in air and water leaks.