Describe where the gap appears
Note whether daylight is visible along the whole opening or mainly at one corner. Mention torn material and any recent change to the driveway or floor. Do not adjust the door’s travel to squeeze the gap shut without having the cause assessed.
Compare seal condition with door position
The flexible seal and the way the door sits are separate questions. A fresh strip may not address an uneven closing position or another underlying problem. Ask the service provider to explain whether the proposed work concerns the seal, door operation or surrounding surface.
Set a realistic objective
Discuss the specific concern, such as drafts or visible deterioration, before approving replacement. A garage door weather seal is not a promise that the opening is floodproof. Keep any separate drainage or building concern in the conversation rather than expecting one accessory to solve it all.
Name the attachment before ordering material
Record the door model if it is accessible and keep the present seal in place for identification. A bottom strip, its retainer and a floor-mounted threshold are different components. Ask the estimate to identify the proposed part, any damaged attachment and what remains outside the repair rather than choosing by width or price alone.
Your questions
Should I buy the thickest seal available?
Choose by compatibility and the assessed problem. Thickness alone does not establish that a seal fits the retainer or the opening.
Can I force the opener lower to close the gap?
Do not use travel or force adjustments as a substitute for assessment. Incorrect changes can create a different operating or safety problem.
Is a new floor threshold the same as replacing the door’s seal?
No. Ask where the proposed component attaches and why it addresses the observed gap. One should not be substituted for the other without assessment.