Garage Door Weatherstripping Replacement: A Complete Guide

The four seals on a typical door

They are separate parts with separate lifespans.

• Bottom seal (astragal): a U-, T- or bead-shaped rubber in the retainer on the bottom section.
• Jamb stop molding: vinyl-flanged trim on both sides and the header that the door closes against.
• Threshold seal: a rubber ramp bonded to the floor, used when the slab is uneven or slopes inward.
• Section weatherstripping: thin strips between sections on insulated doors.

When each one needs replacing

Rubber hardens from UV and heat cycling, then takes a permanent set and stops compressing.

• Bottom seal: every three to seven years in Georgia sun; sooner if cracked or flattened.
• Stop molding: when the vinyl flange stiffens, cracks or pulls away from the trim.
• Threshold seal: when the adhesive lifts or the ramp tears.
• Any seal showing daylight when the door is closed, regardless of age.

Getting the fit right

The bottom seal must match the retainer profile — a T-style seal will not stay in a bead-style retainer, and the wrong size either falls out or holds the door off the floor and trips the opener's down-force. Retainer condition matters too: a bent or corroded aluminum retainer should be replaced with the seal.

Stop molding is set with the door closed so the vinyl flange makes light, even contact along the full height. Too tight and the door drags; too loose and you gain nothing.

After a seal replacement

A new seal changes how the door meets the floor, so the opener's close limit and down-force should be reset and auto-reverse retested. Skipping that step is why some doors start reversing right after a seal is installed.