QMy concrete balcony floor is surfaced with old, discolored outdoor carpet that is coming off in places. I'd like to remove all the carpet and glue and refinish the concrete. How do I proceed? -- B. Shannon

AOutdoor-carpet adhesive is made to resist water and outdoor weather and can be difficult to remove. A method that usually works is to start with a heavy-duty scraper, which can be made from a short-handled garden spade with a flat, straight front edge. Sharpen the edge with a file and use it to whack off as much carpet and adhesive as you can. The short handle lets you put good leverage and power into the scraping. Sharpen the scraper frequently.

When you have scraped off all the carpet and adhesive you can, it is time to tackle the adhesive residue. The adhesive often can be softened with powerful paint removers such as Strypeeze or Kleen-Strip. These products are sold at many home centers and paint stores. Gel-type removers work best. Jasco Sealer and Adhesive Remover and acetone are other solvents that might soften the residue. When using any paint remover or solvent, read and follow the directions carefully; some have strong fumes that can cause health problems if improperly used. Some are highly flammable.

Work on a small section at a time. Covering the paint remover or solvent with a sheet of plastic will help keep it from evaporating while it penetrates. More scraping and several applications of paint remover or solvent might be needed to clean up all the residue.

There is another option: One do-it-yourselfer told me he removed adhesive residue by pressure washing at about 2,300 pounds per square inch. Lower pressures didn't work, he said.

You described a problem called "water hammer" in one of your columns -- a banging or slamming noise in the water pipes when a faucet is turned off. We are having that problem but would like to avoid installing air chambers in the pipes to correct it. Is there a simpler remedy we can try? -- Daoud

The noise is caused by a lack of air in the pipes, leaving no air cushion to absorb the shock when water is suddenly turned off. The problem sometimes can be relieved by introducing air into the pipes. To do this, shut off the water at the main valve and open one or more faucets at the lowest points in the home, usually in the basement. Let the water drain out of the pipes; it will be replaced by air. Close the faucet or faucets and reopen the main valve.

The earth beneath some areas of our concrete driveway and outdoor basement steps has settled so there are only air spaces there. We worry that the concrete will collapse and crack. What do you suggest? -- C. Frost

I would have the driveway and steps examined by a concrete contractor who is experienced in concrete leveling, also called slabjacking or mudjacking. Slabjacking consists of injecting a stable material under concrete surfaces that are sinking because of poor support. The process exerts so much pressure that it actually can raise and stabilize driveways, sidewalks and other concrete construction that have sunk into the earth beneath it.

Unfortunately, slabjackers can be difficult to find. Check the concrete categories in your phone book for possible candidates.

The tub in our upstairs bathroom gets rust stains around the drain. The stains are hard to remove. I have all-copper plumbing and am not getting the stains anywhere else. What's going on? -- R. Ritner

A faucet that constantly drips "hard" water into a tub or sink can leave stains that don't appear elsewhere. It is also possible that this tub has tiny scratches or pinholes in the porcelain coating on the tub, so that water is reaching the metal underneath.

If the faucet is dripping, repair it. If there is no drip, check around the drain for scratches. You might be able to touch up the area around the drain with one of the tub-refinishing kits sold at most home centers and hardware stores.

Try a product called Zud to remove rust stains from plumbing fixtures. It is sold at many supermarkets and effectively removes many hard-water stains, including rust.

Questions and comments should be sent to Gene Austin, 1730 Blue Bell Pike, Blue Bell, Pa. 19422. Send e-mail to doit861@aol.com. Questions cannot be answered personally.