We live in a condominium and areas of our concrete balcony are showing a light green growth (mold?). Would the methods you recently described in your column to remove rust and grease stains from concrete also remove this growth?

We live on the third floor and any chemicals applied would have to be flushed down a gutter that empties to the grass below. Would the chemicals you describe be safe if pets or children come in contact with them? Thank you for your help. -- F.G. There are better ways to remove moss and algae growth from concrete than the formula we described for removing rust and grease stains.

The simplest method is to use a strong solution of household detergent and bleach. Allow the solution to remain on the surface for five minutes, followed by a generous flushing with clear water.

Another effective solution should be a formula of two-thirds cup trisodium phosphate mixed with one-third cup detergent, one quart household bleach and three quarts warm water. Scrub stubborn areas with a stiff brush, then rinse well with clear water.

You might want to place a container where it would catch the solution as it falls from the roofing gutter. Enough clear rinse water, however, should alleviate any problems that could cause serious damage to the lawn area.

A chemical solution that is effective and provides some longer-term protection is copper sulfate, also called bluestone or blue vitriol. This is a chemical you can use to get rid of moss with a minimum chance of harming grass or garden plants.

Sold at feed stores and some nurseries, copper sulfate is available in both powder and crystal forms. The powder is the easier to dissolve in water. Mix one pound of it in 20 gallons of water and either spray or pour it over the mossy area.

Copper sulfate may seem to be staining your paving, but the color is easily hosed off. With proper rinsing, none of these solutions would have any lasting effect that would prove harmful to children or pets.

To help prevent this problem in the future, seal the concrete with aA chemical solution that is effective is copper sulfate. This is a chemical you can use to get rid of moss with a minimum chance of harming grass or garden plants. quality masonry sealer after the surface has been cleaned and is completely dry. Several years ago I made the mistake of painting my concrete basement floor with a high-grade latex paint. It was applied following the manufacturer's instructions.

Now I want to remove the paint without messy sanding -- any ideas? Is there a process where the floor can be soaked to loosen the paint and then scraped? -- D.T. A good commercial paint remover for latex base paint should do the job effectively. Work in one small area at a time, rather than tackling the entire surface at once. Be sure again to follow directions to the letter.

Regardless of the removal method, this is a tedious, messy job. But with patience and hard work the results should be satisfactory. We are contemplating remodeling our kitchen and I would like to install a butcher block counter top. Can you advise me on the pitfalls of this material in the kitchen and its advantages? Any advice you can give me on recommended materials, care and upkeep will be appreciated. -- G.M. Butcher block is a durable product for use in the kitchen as long as it is not exposed to constant moisture, such as in the area directly surrounding the sink. I would advise that you use some other product in this area, such as tile or plastic laminate. This does not prevent the effective use of butcher block on adjacent counters. Maple would be your best choice in wood. It is very hard and dense with a tight grain that won't trap food and moisture.

Your new butcher block counter will require sealing with oil for protection against moisture. At the time of installation, use tung oil to seal both the top and bottom surfaces of the wood. Use ample oil to soak in and remove any excess with a soft cloth. You may want to repeat the process a second time. After its initial sealing, use lemon oil periodically to keep the wood sealed from moisture.

One advantage to butcher block is that it is easily rejuvenated. You can simply sand the surface or go over it with a steel scraper to take off surface scratches and stains. If the blemishes are minor, you can do the work in place. If the wood becomes severely stained or worn, you can remove the counter tops and go over them with a rented floor sander. Oil them again and they look like new. Send inquiries to Here's How, Copley News Service, P.O. Box 190, San Diego, Calif. 92112-0190. Only questions of general interest can be answered in the column.