It's not unusual, though, for older sliding patio doors to show their age. The rollers and tracks are subject to wear, making operation difficult. Handles may break and latches may become misaligned.

A sliding screen is supported on rollers that ride in a track. Lift it until the rollers clear the track. Then, pull the bottom out and lower the door until it clears the top edge of the frame.

If your sliding doors are noisy, hard to open/close, or off-track frequently, it may be time to replace the rollers or tracks. Where to Buy Sliding Door Tracks and Rollers Top Online Retailers ...