09/21/2026
We recently completed a service on a 40+ year old storefront window system that is a perfect case study in seal failure.
During our initial consultation, the entire interior was masked with brown paper for a scheduled painting project. This prevented a full inspection of the gaskets, glazing, and seals. On installation day, once the protective paper was removed, the full condition of the system became apparent.
Every window exhibited significant issues:
• Units were sitting unevenly in the window channel, leaving visible gaps to the exterior
• Heavy contamination and debris buildup within the frame
• Advanced seal deterioration - seals were shrunken, brittle, and in many places, broken or missing entirely
• Excessive movement within the channel, indicating loss of retention
• Evidence of improper prior shimming in the upper portion of the framing
Why Do Window Seals Fail?
Window seals and gaskets are designed to secure the glass, block air and water infiltration, and provide thermal insulation. Over time, due to UV exposure, thermal cycling, and age, the rubber compounds shrink, harden, and become brittle. Once they crack or detach, the system loses its integrity.
The results are:
1. Air & Water Intrusion: Outside elements, moisture, and condensation can seep in.
2. Energy Loss: Gaps force HVAC systems to work harder, leading to higher energy costs.
3. Compromised Film Performance: While window film was applied, film alone cannot compensate for a failed glazing system.
The Correct Solution
For the customer to receive the maximum benefit from their window film investment - including improved solar heat rejection, HVAC efficiency, and lower energy bills - the failed seals must be fully removed and a proper attachment / retention system installed. This restores structural integrity, eliminates infiltration, and ensures the film performs as engineered.