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Module 8 of 10 180m 12 exam Qs

Weatherseal & Panel Maintenance

Weatherseal condition checks, replacement timing, panel delamination, door cleaning, rust prevention, and insulation care.

  • Assess weatherseal condition and determine replacement timing
  • Identify panel delamination and appropriate repair methods
  • Describe steel door cleaning and rust prevention techniques
  • Explain jamb seal compression and side seal function
  • Maintain insulated door thermal performance

Lesson 1

Weatherseal Condition & Replacement Timing

Types of Weatherseals

Garage doors use several types of weatherseals to prevent air infiltration, water intrusion, and pest entry:

  • Bottom seal (astragal) - A flexible rubber or vinyl strip attached to the bottom edge of the lowest panel. It compresses against the floor to create a seal.
  • Side seals (jamb seals) - Vertical weatherstrip mounted on the door jambs that compress against the door edges when closed.
  • Top seal (header seal) - A horizontal strip across the top of the opening that seals the gap between the top panel and the header.
  • Panel-to-panel seals - Flexible strips between each panel that prevent air and water from passing through the joints.
A
Bottom Seal
Floor contact - most wear, replace most often
→
B
Side Seals
Jamb contact - moderate wear
→
C
Top Seal
Header contact - least wear
→
D
Inter-Panel
Panel joints - check for compression loss

When to Replace Weatherseals

Replace weatherseals when:

  • Cracking or splitting is visible in the rubber or vinyl
  • Hardening has occurred - the seal is no longer flexible enough to compress
  • Gaps visible with the door closed - daylight or air drafts pass through
  • Tears or missing sections leave unprotected gaps
  • Bottom seal dragging or folding under instead of compressing flat
✅

Bottom Seal Types

Bottom seals come in T-style (fits a retainer channel) and beaded (snaps into a groove) configurations. Always identify the correct type before ordering a replacement. Measure the width of the retainer channel to ensure proper fit.

Key Takeaway

Inspect all four weatherseal locations at every visit: bottom, sides, top, and inter-panel. The bottom seal wears fastest due to floor contact. Replace any seal that shows cracking, hardening, gaps, or tears. Match the correct seal profile (T-style or beaded) to the door's retainer system.
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