Q) What can be done to eliminate the "green" appearance that develops on exterior north-side stucco walls? -- J.J.M.

A) This is a type of fungus that is usually caused by dampness. Large trees and shrubbery next to the building, or even adjacent buildings, can aggravate the problem because they prevent exposure to sunlight and maximum air circulation.

Often simply scrubbing the area with a stiff brush will remove the growth. For best results, I suggest that you use a solution of two-thirds cup of trisodium phosphate, one cup detergent, one quart household bleach mixed with three quarts warm water. Allow the solution to soak for about five minutes, scrub with a stiff brush and flush with water.

If you are concerned about continued growth, particularly if the area stays shaded and is damp much of the year, treat the wall with one of the stronger chemicals available.

Copper sulfate, also called bluestone or blue vitriol, is a chemical that will eliminate moss with a minimum chance of harming grass or nearby plants. Sold at feed stores and some nurseries, it is available in powdered and crystal form.

The powder is the easier to dissolve in water: Mix 1 pound of it in 20 gallons of water and spray over the mossy area. Copper sulfate may seem to stain your stucco but the color is easily hosed off.

For future protection apply a good masonry sealer over the surface when it has dried. There are mildew-resistant paints that will help protect the area.

It is best to leave the chemical treatment and any sealers or painting until after the rainy season.

Q) I recently moved into a rental home. The living room carpet smells strongly of pet urine and although it has been shampooed repeatedly nothing seems to be working.

I have been told that the only way to solve the problem is to have the carpet replaced. Is there any other solution? -- M.J.M.

A) This is a very difficult stain and odor to remove. The urine has most likely penetrated not only the carpeting but also the carpet padding, and the flooring beneath.

Start by removing all carpeting and padding. Thoroughly clean the flooring. Use strong cleaners that contain ammonia. White vinegar is another ingredient that is helpful in removing odors.

When the flooring is thoroughly dry, apply a sealer (Thompson's Water Seal is one recommended product). Put down new carpet padding. Have a professional inspect the carpeting to see if it is worth saving. It could be that with professional cleaning and deodorizing you can have it relaid.

Q) We recently purchased a 13-year-old home. The tub and shower are plastic and the finish is worn. Also, rubber pieces have been used to prevent slipping and we are having difficulty removing them. I hope you can help us. -- F.J.P.

A) If this is an older tub/shower it is possible that wear and tear have caused permanent discoloration.

Try using a thick paste made of scratchless scouring powder, a little cream of tartar and peroxide. Rub this on the worn, yellowing areas and allow to remain a half hour. Rinse with clear water. You can also try commercial fiberglass cleaners, readily available through a marine supply dealer.

Rent a buffer after cleaning and use this to polish the surface.

First you will want to remove the rubber adhesive strips. Try using Spray and Wash, letting it soak on the rubber strips to soften the adhesive. Lemon oil is also sometimes effective. Or, try this, supplied recently by one of our readers:

"I read your article about removing bathtub flowers and I bring to you the easiest, safest solution to this problem. Some years ago I represented Rubbermaid in home sales demonstrations. Although we didn't sell these flowers, we were often in the middle of the flower/customer/company problem. Eventually Rubbermaid gave us an efficient solution that satisfied everyone.

"Peanut butter, yes, peanut butter, applied around the edges of the flowers worked. The explanation given to us was that the oil in peanut butter was able to break down the adhesive if given enough time, usually overnight. It works, it's safe, and because it's edible, you know it's biodegradable. Use it, share it, enjoy it, and when you are through laughing you will also agree that itworks -- J.R.D."

Send inquiries to Here's How, Copley News Service, P.O. Box 190, San Diego, CA 92112-0190. Only questions of general interest can be answered in the column.