Q: A former tenant sloppily painted over the glazed tile in the bathroom of our 1910 apartment. Will chemical paste-type paint removers damage the tile or the grouting if used according to directions?

A: Paint remove will not harm the tile or grout, but remember that you can scatch it with a putty knife or similar tool used to remove the softened residue -- so work carefully. Better yet, use water wash-type remover; that way you can remove the residue with a stiff brush dipped into water and detergent, rather than by scrapping with a metal tool.

Q: I have a composition roof on my house which is about five years old. The roof has developed air pockets or bubbles and I would like to know if a do-it-yourselfer can make repairs to eliminate this problem so that my roof can be tarred.

A: First of all, if there are no leaks, and if the composition is not cracked where the bubbles are, then I would not worry about those areas. Air pockets are a frequent problem on composition roofs, but they generally cause no trouble for quite some time if left alone, and if not walked on.

However, if you want to get rid of them, here is one way to do it: Slice through the middle with a sharp knife, then use a small trowel to work roof cement under both sides of the bubbles. Press the raised material flat, and fasten down with roofing nails along each side of the cut to hold it down. Cover the entire area with another layer of roofing cement, then on top of this position a sheet of heavy roofing felt. Drive more nails around the edges of the new patch and cover the nails head with roofing cement.

Q: The former owner of my house must have had water problems in the basement and tried to solve them with an epoxy sealer, and by injecting chemicals into the soil around the house. This has been only partially successful. A contractor now suggest digging drainage channels around the perimeter of the floor and then installing perforated plastic pipe that will be connected to a sump pump. He assures me this will keep the basement dry. Is this method often recommended?

A: This a "pressure relief" system -- often the only solution to severe problems with water in the basement. If done properly by a competent contractor, it almost always solves the problem.

Q: I want to put a hardwood floor down on top of the bare concrete floor in my basement, instead of putting down carpet. Is a vapor barrier needed between the plywood and the concrete, and are there other steps I must take to protect against moisture?

A: If there is a moisture condition present in that floor, don't put the wood flooring down until you solve it. When you do decide to go ahead, make sure you buy the type of laminated flooring recommended for installation below grade. Usually a moisture barrier will be recommended, but specific details about what to use and how to install it usually are included when you buy the flooring.

Q: Even though my floora are carpeted, they still squeak. Is there any way to stop the squeak in hardwood floorboards?

A: Floorboards squeak because one or more are slightly loose so that they move up and down when stepped upon. The edge of one board rubbing against the edge of another is what causes the squeaking sound. Carpet may muffle this noise, but it won't stop it.

The only permanent cure is to refasten the loose boards by driving nails through the edges to hold them down. This means rolling the carpet back, then locating the boards causing the trouble by stepping on each one. Drive nails in at a 45-degree angle so they penetrate the tongue edge of each board then countersink the head so it won't be noticeable.

Q: I would like to refinish two 30-year-old pitted aluminum doors. The liquid aluminum cleaners I tried did no good. Should I use a steel brush and then paint the doors white or aluminum?

A: I suggest a thorough cleaning with strong detergent, then rubbing with steel wool until the surface feels reasonably smooth. Use medium grit wool first, then fine. Wash clean again and allow to dry thoroughly. Apply metal primer suitable for use on aluminum and follow this with a coat of white or aluminum exterior trim enamel.