Red Seal Glazier Practice Exam

Identify a common cause of seal failure in insulated glass units.

1. Excessive weight on the glass

2. Improper installation

3. Using glass that is too thin

4. Extreme weather fluctuations

The correct answer is: Improper installation

Improper installation is a well-documented cause of seal failure in insulated glass units. When insulated glass is not installed correctly, it can lead to a variety of issues that compromise the integrity of the seals. For instance, if the spacer bars are not aligned properly or if the unit is not adequately secured in its frame, stress can be exerted on the sealant. Additionally, using inappropriate materials or techniques during installation can lead to weak points in the seals. Over time, these weak points can allow moisture and air to infiltrate the sealed unit, resulting in fogging, condensation, and a significant reduction in the thermal performance of the glass. While excessive weight, using glass that is too thin, or extreme weather fluctuations can certainly impact the performance and durability of insulated glass units, the direct correlation between improper installation and seal failure stands out as a primary concern. This is why proper training and adherence to industry standards during installation are critical to ensuring the longevity and functionality of insulated glass.