Locate the gap
A gap at one corner is different from a split bottom seal along the full width. Describe the pattern without reaching beneath the door or adjusting its travel.
Check the seal and its fit
Replacement profiles need to suit the existing retainer and door. The floor surface and the way the door sits can affect the finished seal.
Set realistic expectations
Weather seals help close ordinary gaps. They do not turn a garage door into a flood barrier or correct a door that is out of alignment.
