Under Pressure: Valve Problems Plague Tub

QUESTION: The water pressure in our tub is good. However, when we turn on the shower, some water continues to come out of the tub faucet, and the water pressure from the shower is reduced. How can we correct this problem?

ANSWER: The problem is with the tub-shower diverter valve. When the valve is functioning properly, all the water should be channeled to the tub or shower.

There are two common types of diverters. In the tub spout diverter, a small gate valve is attached to the base of a plunger shaft located in the spout. It is held in the up position for the shower by water pressure. When the water is turned off, the gate drops and opens the tub spout. To remove it for repair, unscrew the tub spout from the threaded water pipe.

The other diverter works by rotating the valve stem so the parts in the valve body open to either the tub spout or the shower pipe. You can remove the mechanism by unscrewing the stem nut and withdrawing the diverter assembly.

Tub diverter spouts and diverter assemblies cost $10 to $15 at plumbing supply stores. Since there are different types and sizes of tub-shower diverters available, take the old one with you to make sure you get an equivalent replacement.

Clean Track, Wheels to Keep Doors Sliding

Q: I live in a condominium that is 17 years old. The glass and screen doors have become a major problem, and the owners are getting conflicting information on how to keep them opening and closing smoothly. The doors lift up and pull out, but most of us are not strong enough to do this. What is the best way to maintain these?

A: Once the doors are no longer sliding smoothly, get someone to lift them out of their track. Then, clean around the bottom wheels. Over the years, hair, dust and dirt accumulate around the wheel bearings, constricting them.

If the doors slide smoothly, the best way to maintain them is to keep the channel track that they slide in clean by periodically brushing it out or vacuuming it with a narrow nozzle. Wipe out any remaining grit with a damp sponge, dry the channel, then lubricate it with powdered graphite or a silicone spray.

Black Spots on Ceiling Are Probably Mildew

Q: The cathedral ceiling in my 10-year-old house was OK until five years ago, when we noticed black spots appearing through the sand finish. I painted it and it looked good but the black spots came back. I have asked many carpenters what causes it, but none seem to know. Can you help?

A: The black spots are probably mildew spores. Mildew is a fungus and unless you kill it, it will come through a new layer of paint, especially a water-based paint. Try washing the ceiling with a solution of bleach, detergent and water. After the ceiling is dry, paint it with a mildew-resistant paint or use a fungicide additive in the paint.