Patio Door Stiff To Slide Or Off Its Track

What's happening?

DoorsDirect2U, which sells sliding doors, says dirt, grit and pet hair in the bottom track are the main cause of sticking and of doors that only seem misaligned. The grit wears the rollers, lowers the sliding sash and pulls the lock out of line. Three checks separate the causes. A door that drags or clicks over the track has a dirty track or flat-spotted rollers. A door tight at the top and loose at the bottom has dropped on its rollers. A handle that needs force to hook shut has a sash that is too low or a keep that is out of line. Worn brushes or seals let in draughts and rattle, mist between the panes means a failed sealed unit, and gaps that change with the seasons point to a frame that has moved.

What usually causes it?

• Dirt, grit and pet hair in the bottom track
• Rollers that are worn, flat-spotted or out of adjustment, so the sash drops
• A lock keep that has gone out of line with the hook
• Worn brush seals or weather seals
• A frame that has bowed or moved
• A sealed unit that has failed, making the glass heavy and misted

Is it dangerous?

No. A door that will not hook shut is a security weakness, so do not leave it unlocked. Do not force a stuck sash: glass doors are heavy and can come out of the track.

Can I fix it myself?

Vacuum and brush the bottom track and wipe it clean, then clear the drainage slots in the outer track. Use a silicone-based lubricant on the rollers, not oil, which attracts grit. If the door still drags, the roller adjusting screws sit near the bottom corners of the moving sash: turn each a small amount, test, and keep to the manufacturer's instructions. Do not over-adjust. If the door drops again within days, or the rollers are cracked or wobbling, stop.

When should you call a window fitter?

Call a window and door fitter if cleaning and a small adjustment do not free the door, if the rollers are worn or cracked, if the glass has misted, or if the frame looks bowed. Ask them to check the track and the frame before replacing parts.

What will the window fitter actually do?

• Clean and inspect the track, rollers and brush seals
• Adjust or replace the rollers and square the sash in the frame
• Realign the lock keep so the hook engages without force
• Replace worn weather seals and brushes
• Check the frame for movement and replace a failed sealed unit if needed

Who fixes this

• Bifold and patio doors
• Window repair and adjustment

Questions people ask

Sources & References

1. DoorsDirect2U: how to adjust sliding patio doors
2. DoorsDirect2U: common sliding patio door problems