Sliding patio-door alignment problems
A panel that rubs, sits crooked, or whose latch misses the keeper is usually an adjustment question, sometimes a frame question, and never a foundation diagnosis from this site.
Visible symptoms
Stand inside with the door closed and look at the gaps. A well-aligned sliding panel shows an even gap along the top and meets the fixed panel's edge evenly from top to bottom. A misaligned one shows a wedge-shaped gap, rubs the head or the sill at one corner, sits visibly lower at one end, lets light or air through at a corner, or brings the latch hook to a point where it cannot reach the keeper. Manufacturer troubleshooting lists panels that do not line up at the meeting stiles as a cause of a door that will not close, and worn weatherstrip or a misaligned pile pad as causes of light and air leaks at corners.
How rollers, track and hardware interact
Alignment is not a separate part. It is the result of the rollers' height at each end, the condition of the track they ride on, and the frame the panel sits in. Roller height adjustment is the tool for correcting it: screws at each lower end of the sliding panel, sometimes behind small plugs, raise or lower that end of the panel. Manufacturer guidance is specific about limits. Adjusted too high, the door can allow water and air leakage; too low, it drags on the track; the aim is to clear the track with the weatherstrip hidden when the door is closed. The same guidance notes that the direction of turn to raise the panel differs between door lines, so a technician checks rather than assumes. Once the panel is set, the latch hook's reach can be adjusted on many locks, and the keeper repositioned, to restore locking. The roller page and the lock page cover those parts.
Why frame conditions may need a separate assessment
If the frame itself is no longer square, if the sill has bowed, or if the corners have opened, no amount of roller adjustment holds. Those conditions need a broader look at the door unit and the opening, and they are one of the things the repair-or-replace guide is for. Two things this site does not do: it does not diagnose foundation or structural movement from a sticking door, and it does not turn an alignment inquiry into a structural repair recommendation. A door out of square has many possible causes, most of them local to the door, and a sticking door is not evidence of anything about the house. If a technician sees something that warrants a separate structural opinion, that is a separate conversation with a separate professional.
Information to supply
Photographs of the gap along the top of the sliding panel, of the meeting stile from top to bottom, of the bottom corners where the panel meets the track, and of the latch and keeper with the door closed. Say whether the door has been adjusted before, whether the symptom changed suddenly or gradually, and whether the door leaks air or water. The photo guide has the full list; do not remove or lift the panel to get a better view.
Options and exclusions
The options, in the order a technician usually tries them: clean the track; adjust roller height; adjust the latch and keeper; replace worn rollers; repair or cap a worn track; and, if the frame is the issue, assess the unit. Exclusions: glass, whole-door replacement, and any structural work on the opening. Which of these applies, and at what price, is settled on site rather than on this page.
Inquiry
Describe what you see on the contact page and choose the "rubs, sits crooked, or gaps" category, or "not sure". The operator reviews every inquiry and responds with the next step; sending the form is not a booking. For the general sorting of symptoms, read why your sliding door is hard to open.
Questions on this page
Why will the latch not engage?
The latch hook has to meet its keeper. If the panel has dropped at the lock end, or the keeper has loosened, the two miss. Manufacturer guidance lists panels not lining up at the meeting stiles as a reason a door will not close, with roller adjustment as the fix, and separately lists loose or damaged keepers. Adjusting the panel height often restores the latch; if it does not, the lock itself is the next suspect.
Why does the door rub?
A panel set too low drags on the track; one set too high can rub the head or let air and water in; one higher at one end than the other rubs at a corner. Uneven roller wear, a roller dropped out of adjustment, or a track worn at one spot all produce it. Adjustment is the first step; worn parts are the second.
Is a hardware adjustment enough?
For many doors, yes: the height adjustment screws at each lower end of the sliding panel are designed for exactly this. If adjustment reaches its limit and the door still rubs, or if the problem returns quickly, something else is wearing or moving and needs to be found.
What cannot be diagnosed remotely?
Whether the frame is square, whether the sill is level, whether the rollers or track are worn, and whether the door can be brought into alignment without parts. A photograph of the gap along the top and the meeting stile helps, but the judgement is made on site.