Red Seal Glazier Practice Exam 2025 – The All-in-One Guide to Master Your Certification!

Testing the seal on insulated glass is important to ensure its effectiveness in preventing heat loss and moisture ingress. The correct method involves performing a visual inspection for fogging, moisture, or dirt accumulation between the panes. If there are signs of moisture or fogging within the sealed unit, it indicates that the seal has failed, allowing air and moisture to enter the space between the panes. This visual evidence is one of the most straightforward and effective ways to identify seal integrity issues.

The other options, while related to glass inspection, do not specifically address the efficiency of the seal. For example, checking the edges for scratches may indicate surface damage but does not necessarily reflect the condition of the seal itself. Applying pressure to the glass may test for robustness or adhesion but is not a definitive test for the seal's integrity. Measuring temperature differences can suggest issues related to insulation but does not directly confirm whether the seal is compromised. Thus, the visual inspection stands out as the most direct and conclusive method for assessing the seal on insulated glass.