Sliding door repairs are discussed in this article; for repairs to patio and entry doors, please see How to Repair a Door.
When a sliding door doesn’t work right, the problem is often that the rollers have come off the track, so first check to be sure they’re fitted onto the track properly.
To repair a sliding door, you have to remove it. How you remove it depends on the way it’s supported by its frame.
Lift a bottom-supported door straight up to clear the bottom track. Then sharply angle the bottom of the door outward, and lift the door from the track. Be careful—sliding doors can be very heavy!
A top-hung door can be lifted straight up and then angled to lift the rollers from the track. You may need to align notches on the track with the rollers before you can lift the door out.
Inspect the door’s rollers to see if they’re broken or have come loose. If the problem is just a loose roller, tighten or replace the loose screws at the base. Most top-mounted sliders have a simple adjustment on the top roller bracket. If a roller is broken, you’ll have to replace it (take it to the hardware store to find an exact match).
Check the track to see if it is worn or bent or if the guide is misaligned. Misaligned rails can be knocked back into alignment with a hammer and a wooden block. Rail guides can be repositioned by merely tightening the screws that hold them in place. You may need to unscrew and reposition them, and then retighten the screws.
If a malfunctioning sliding door is a chronic problem, see if the track is dirty. Built-up dirt or loose debris can cause a door to stop sliding and ride off the track. Use a wire brush to clean off the dirt or debris. Use the blade of an old screwdriver to pry stubborn dirt loose. Once you’ve cleaned the track, lubricate it with silicone spray or a little paraffin to help the door ride smoothly; this is good periodic maintenance to prevent problems. In addition, a drop of penetrating oil on each roller can keep the door moving smoothly and quietly.
Sometimes, with a sliding door, it isn’t the track or rollers working improperly, it’s the catch. To reshape a bent catch, remove it and clamp it in a vise. Using pliers or a hammer, bend the catch to the proper angle. Then replace it and check the latch operation; it should click as the door closes, and it should have to be depressed fully for the door to open. Replace a malfunctioning catch or one that is worn or broken with the same model.
If you’re in the market for a new sliding door, check out the latest offerings with wood surfaces that face into a room and vinyl or aluminum cladding facing the outside. These give you the best of both worlds—beauty and durability. See Patio & Sliding Doors Buying Guide.
Featured Resource: Find Local Pre-Screened Sliding Door Repair Pros