For The Associated Press

Q: My house has a set of sliding glass doors that are about 20 years old. One of them is difficult to open and close. The track is OK. Could it be the rollers that need replacing?

A: You bet! If the door is made of steel or aluminum, the rollers are usually made of nylon or soft metal that wears out all too easily. The good news is that most good hardware stores offer a large selection of replacement rollers. Naturally, it is better if you purchase the proper rollers from the original manufacturer, although most replacements will work pretty well.

But before you go to the store looking for new rollers, try adjusting the ones that you have. It just might be that they are slightly worn, not broken, and simply need to be adjusted so that the door doesn't drag on the track. The door has an inside and outside face, a top and bottom edge, and a left and right edge. The screws that adjust the rollers are located about an inch above the bottom of the door.

One is on the left edge and the other is on the right edge. Use a flat pry bar to lift the door. This will take pressure off of the roller and make it easy to turn the adjusting screw. Don't turn the screw more than one turn at a time. If the problem gets worse, you probably turned the screw in the wrong direction.

Tips:

You've just laid tile and added grout. Now it's crumbling and coming out. You can end this problem if you know the five steps to grouting success.

* If you have a wood subfloor, be sure you use a concrete backer board.

* Make sure the thin-set mortar is not too dry.

* To check, lay a tile and pull it up to make sure at least 75 percent is covered.

* Don't mix up more mortar than you can use in a half-hour.

* Mix your grout with an acrylic additive and use sanded grout on all joints over 1/8-inch wide.

If you follow these five simple steps your grout will never turn into a crumbling mess and your kitchen or bathroom floor will stay good as new.