Definition
A complete garage door weather-seal system has four components:
- Bottom seal (astragal), a U- or T-shaped rubber strip in a track on the bottom of the door. Compresses against the concrete to seal out water and pests.
- Side seals, vinyl strips nailed to the door jamb that compress against the door when it closes.
- Top seal, similar to the side seals, sealing the top of the door against the header trim.
- Inter-panel weather stripping, built into the joints between door sections, sealing the panel-to-panel gaps.
The bottom seal is the most failure-prone, UV exposure, concrete grit, lawn-mower contact, and the constant compression-release cycle wear it out long before the door panels themselves need attention.
Why it matters to Nashville-area homeowners
In Middle Tennessee, a degraded bottom seal is the difference between a dry garage and one that floods during a summer downpour. We recommend a perimeter seal inspection every spring, the bottom seal especially. Replacement is a 30–45 minute job that any technician can do at the end of a tune-up visit, and it pays off the first storm of the year.
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How this definition is reviewed
Definitions reviewed against UL 325 (Underwriters Laboratories Standard for Door, Drapery, Gate, Louver, and Window Operators), CPSC 16 CFR Part 1211 (federal residential garage-door-operator safety rule), DASMA technical data sheets, and current manufacturer specs from LiftMaster, Chamberlain, Genie, Clopay, and Amarr. Locality notes draw on in-the-field experience in Middle and East Tennessee homes built between the 1960s and the present.
