The easiest way to solve this problem is when installing the door space the jambs off the floor when possible.
One side of garage door higher than other.
The door should be parallel to the header.
If the concrete sags on one side you do not adjust the door to fit it.
I ripped off the old bottom seal since one side of the garage always got wet in rain or snow and i could see that the seal was deteriorated at that side so went and got a new seal removed the old one sanded it slightly then applying the new seal that one side still has 1 2 space higher than the rest of the door.
Chord length on shaft.
Doors also rise on one side when the cable is not properly seated on the cable drum on the opposite side.
A crooked garage door could potentially be the sign of a much larger problem.
Maybe someone bumped into it recently.
The replacement garage door should be one that hangs above the front of the garage and lowers down from the outside so it doesn t affect the height of the garage.
The door runs are housed in a garage door track one on each side of the garage door.
Adjust the springs on both sides of the door the same way.
An alternative would be a pocket garage door that slides sideways on tracks from within the garage door itself so that again the height or width are not effected.
Or it could just be that the hardware has become loose over time.
If it was opening too quickly move it to the next lower hole.
This can happen when the door has shifted to one side causing it to appear uneven.
Arc length on shaft.
If you ve had your door for a while or are in and out of it a lot it can easily end up out of alignment.
It also depends a lot on the number of years the door has been up as it could be that the door springs have become worn.
If you have a 1 gap under the door it isn t necessarily that the door is crooked.
There are several things that can cause this.
The most simple and common is door shift.
It may be the spring.
When the door is placed directly on the floor and it s not level it causes one side of the door hinge or latch side to be higher than one another.
When this happens you need to shift it back into position.
If you mean that one side of the garage door is lower than the other and that it hasn t always been this way then you do have a problem.
If the door was closing too quickly move the spring to the next higher hole on the bracket.
The most likely cause is that the floor is not perfectly level.