Describe the finished surface, not just the current slab
Tell the flooring provider and door installer what material is proposed and whether the finished level changes near the opening. Include any planned threshold or drainage work. This helps both trades discuss the same final condition. A quote prepared against the existing slab may not account for a later change at the door edge.
Keep door adjustments out of the flooring shortcut
If the door no longer closes normally after floor work, do not increase the opener force or alter loaded hardware to make it fit. Have the fit and travel assessed. The bottom seal, door alignment and surface condition need to be understood together; stacking materials under the seal can hide a problem rather than solve it.
Agree on sequence and access
Ask how long the opening must remain accessible and how vehicles and stored items will be managed. Keep an alternate entrance available without relying on an elevated door as a permanent position. At handover, review the door’s normal operation with the finished surface in place. Any remaining gap or water concern should be explained rather than covered by a blanket promise that the garage is waterproof.
Your questions
Can a thicker bottom seal compensate for every floor change?
No. The correct seal must suit the retainer and door condition. Changes in floor level may need a different assessment.
Should I adjust the opener after a new floor is installed?
Do not make force adjustments to overcome interference. Report the changed closing behavior and have the assembly checked.