The kids and the dog have been in and out of the sliding screen door all summer, and the thing is getting harder and harder to open and close. The screen door hangs up, sticks and skips when pushed, and opening and closing it is starting to take some real strength.

Fixing the screen door is usually a job put off until spring, but there may be a few more days of Indian summer coming, and it would be nice to enjoy the good weather.

One of the most common mistakes people make with their sliding screen doors, says Cary Hayden, owner of Bend On-Site Screening, is to put some sort of lubricant on the track.

“Don’t ever lubricate the track, that will just attract dust and dirt and gum it up,” Hayden said. “If the door doesn’t slide cleanly, it won’t work any better with lubrication.”

A combination of problems can cause a door to stick or not move easily, Hayden said. To figure out why the screen door is sticking, look first at the frame.

“If the frame is bent, it needs to be replaced,” Hayden said. “About 99 percent of the time, the frame will be bent right in the middle by the latch.”

The frame gets bent when the door is partially open and someone bumps or walks into it.

“Once the frame is bent, it is really weak in that spot, and the frame won’t stay straight, and it will probably bind,” Hayden said. “The best thing is to replace it.”

Make sure the frame isn’t bent, then remove the unit by pushing up on the wheels at the bottom and lifting the door out. There is an adjustable, spring-loaded wheel at each corner.

Examine the wheels and make sure each spins freely, then examine them closely to make sure they aren’t broken and that there are no flat spots. If the door is jerky and skips, that could be a sign of a bad or broken wheel or a nick or damage on the track.

Repair may be as simple as replacing a broken or damaged wheel. While the door is off, examine the track. A bent or gouged rail can contribute to the sticking problem, and fixing the door may require filing out the gouge or straightening the rail.

Once you’ve determined that the rail and wheels are OK, it’s time to adjust the door so it will slide freely.

“Back the wheels off until they retract completely into the door frame,” Hayden said. “Put the top of the door into the frame first, then use a putty knife or screwdriver to push the wheels into the frame while you position them on the rail.”

At this point, turn the adjustment screws on the bottom wheels down until they are snug, and slide the door back and forth to see if it moves freely and goes easily into the door jamb. As you move the door back and forth, you might find a tight spot in the middle of the door jamb.

“Frequently, vinyl door jambs will sag with time, and create a low spot that causes the door to bind,” Hayden said. “If you find a low spot, slide the door there to adjust the wheels.”

Adjust the bottom wheels first, Hayden advises, then tighten the top wheels.

If the frame is not bent, the wheels are working freely, the rail is straight and cleaned and not lubricated, then the door should slide more smoothly.

If it doesn’t, the screen door may have design problems that will require an expert to fix. Many commercial patio door units come from the factory with a screen door that is too long, Hayden said, and when the vinyl top rail starts to sag with age, that door will have to be replaced.

“When you push the top of the door completely in, you want at least 3⁄8-inch space at the bottom between the edge of the door and the edge of the track,” Hayden said. “If you can’t (open) the door in without rubbing metal, it’s too tall.”

If your screen door has a hole or tear in it, that’s fixable, too. The entire mesh screen can be removed by taking out the spline, a rubber or plastic cord that holds the screen in a groove around the outer edge of the door. Lay a new piece of screen material over the entire frame, then, using a spline roller and making sure the screen is taut, press the spline into the groove over the new screen material. Trim any excess from the frame.