Question: The basement floor in my 1960s house has vinyl tiles that have deteriorated from dampness and come loose, and so has the concrete under them, making a very uneven surface. Some 24 tiles are involved, and there is efflorescence (white powder) under them. How can I smooth out that concrete before putting down a pad and carpeting? -- Arthur Chamian, Lynnfield, Mass.Answer: Tiles installed in the '60s could be vinyl-asbestos; if they are 9 by 9 inches and very rigid, chances are they are vinyl-asbestos; if you want to remove them, have them checked by an asbestos abatement company. According to the amount of asbestos they contain, they might need professional removal. If the asbestos is at a certain level, you can remove them yourself. Or, leave them intact; asbestos tiles left intact are not harmful, and can be covered with carpeting or other tiles. To smooth the deteriorating concrete, sweep out the efflorescent powder, fill the rough areas with floor-leveling compound, let set and sand smooth. Glue the tiles back with tile cement or adhesive caulk. Install a synthetic jute pad and the carpeting on the smooth, even tiles.
Question: My shower is 3 years old, and now when I turn on the one-handle valve, water rumbles and pulsates, getting stronger and stronger. What's wrong? How can I fix it? -- Linda Carp, Sharon, Mass.
Answer: The pressure may be high. Have a plumber check it and put a pressure-reducing valve on the main intake line, if necessary. If pressure is not the culprit, then it's the valve.
One-handled pressure-control valves are sensitive, and a bit of grit in one can knock it askew. Sometimes taking the valve apart and reassembling it will work; if not, the valve should be replaced. Unless you are comfortable with plumbing, hire a plumber to do this.
Question: I left a folded Oriental rug on my deck for five months. Needless to say it is moldy. I had a it professionally cleaned and I scrubbed it myself, without much success. Now what? -- Deborah Nagler, Concord, Mass.
Answer: The more sun you can get on it, the better. Both sides, too. If it is not too big, hang it over a clothesline. And try this: Wash it with Era, a detergent that contains oxygen (not chlorine) bleach, which will attack any lurking mold.
A final try is to make a mix of one part household bleach and 10 parts water and wipe this lightly on the back of the rug. But first try it on an obscure area to make sure it does not bleach out the colors. If colors fade, even a little, stop. The solution is too strong. If colors show no sign of fading, wipe both front and back lightly with this solution. Squeeze out a sponge in this solution to make sure the application is light. Wear skin and eye protection when working with bleach.
Question: I put up a prefab shed in my yard last fall. The floor is plywood; do I have to treat it? There is a little outside ramp of pressure-treated plywood. Does that have to be treated? Finally, there is vinyl siding on this shed; should I caulk the ends or any joints? -- Jay Pederson, Littleton, Mass.
Answer: No to all three questions. The shed floor is exterior-grade plywood, or at least should be, and does not have to be treated unless you want a color. If you like the idea of a color, use a semitransparent stain. This stain (only one coat is needed) will also provide a modicum of resistance to wear and tear. The pressure-treated plywood ramp does not have to be treated; it is best left alone. Do not caulk any ends or joints in the siding; vinyl siding is designed to shed water, and any corners or joints where so-called J-channels are installed (where the siding meets trim, or window or door casing, for example) are designed to let water flow around them and through them out of harm's way. Caulking could block this flow. So, you can relax and enjoy your shed.
Question: My concrete front porch had minor repairs made, but now the new concrete patches are quite different from the old. How can I make them the same color? --Harvey Cote, Arlington, Mass.
Answer: Wait a few years; the new concrete will weather to match the old. But for instant color, give the porch a coat of concrete stain. Muralao makes one in many color choices. The stain will not peel. Do not paint the concrete; you are likely to end up with a perennial headache of scraping and repainting the peeling paint.
Question: All my walls are finished with flat oil paint. Can I put acrylic or latex paint over it? Is any special prep to be done? --Herbert Shivek, Brookline, Mass.
Answer: Latex or acrylic can go over an old flat oil finish. There is no special prep needed, but I suggest you sand the walls lightly with fine sandpaper, then wash them with a strong solution of Spic and Span and water before applying two thin coats of the wall paint.
Globe Handyman on Call Peter Hotton will answer reader questions. Write him at the Boston Globe, Boston, Mass., 02107.