C.S., Reading

A. One thing to consider before doing the job: Don't do it. Brick is OK, generally, as a decorative material, and it is the way the builder intended it to be. If you do install the tiles, using thin-set or adhesive, it will be the very devil to take off, if anyone wants to.

That said, dry brush the brick and install the tile with thin-set mortar, despite what you were told that thin-set will not stick to brick. Thin-set was developed to stick to any masonry, and that includes brick. The Handyman put a border of tiles on one of his fireplaces (but it's only a border, where the tiles were needed), and they have stuck tenaciously for 20 years. Incidentally, thin-set will stick to most wood surfaces as well, and most other materials, except maybe fiberglass insulation and plastics such as Styrofoam.

Heat from the fireplace will not hurt the tile; after all, the tile was fired at higher heat than the fireplace can produce. You can put the tile on the front of the fireplace and on the hearth, but not in the firebox.

Q. I plan to put ceramic tiles on my bathroom floor. The house is nearly 70 years old. There is vinyl flooring there now, and I was told that under that vinyl is asbestos. What can I do now before putting in the ceramic tile?

BILL GENTLE, Arlington

A. You won't know what is under the vinyl until you test both the vinyl that's on the floor now and anything underneath. Sheet vinyl, installed as recently as 15 to 20 years ago, may have a white or gray backing; if so, it is probably asbestos. Break off a small piece and have it tested by an asbestos abatement company (in the Yellow Pages). If there is no asbestos, you can go ahead and scrape up everything to the wood floor. Then put down a sheet of concrete board (WonderBoard is one brand), and apply the tiles with a thin-set mortar. You could do the same over the existing sheet vinyl.

Q. My attic ceiling tiles have a lot of water stains. How can I cover them? I heard I could get rid of them with bleach and water.

K.M., Milton

A. Some people have had luck with bleach and water in removing water stains. But, even if this works, they may come back. Besides, the tiles are fibrous and might react adversely to the bleach. It is better, in my opinion and my experience, to seal in those stains with clear shellac, then repaint the ceiling. You could try repainting just the affected tiles after using the clear shellac, but that way you would probably never get any two tiles to match.

Q. I am replacing the ceiling tiles in my bathroom. I found the flat, smooth, painted tiles you mentioned that are washable (as opposed to acoustical tiles with holes or fissures), but the people at Home Depot said the tiles will not hold onto the ceiling in a damp environment. I am concerned about that because part of the ceiling is over a tub shower. Will the tiles work in that area, and more important, will they hold?

ED TAKACH, Arlington

A. Nothing much of anything will stick well on a damp surface, but you should be able to put up the tiles with adhesive if the surfaces are dry, because most adhesives for ceiling tiles are water resistant, and are generally unbothered by moisture. And, if you are reluctant to use adhesive, you could install 1-by-3-inch strapping to the ceiling, then staple the new tiles to that strapping.

And, while you are at it, consider putting in an exhaust fan. Properly used, this fan will keep the bathroom as dry as it ever will be.

Q. I clean my ceramic tile floor to get rid of the grout left on the face of the glazed tile. It's only a film, not big chunks, but when I wash it, it comes right back when it dries. Now what?

DAVID DuVERNAY, Rindge, N.H.

A. A film of grout is indeed a pain, a little like plaster dust that cannot be washed off; you wash it and it comes right back. So, for the grout film, polish the face of the tile with a dry cloth. If that doesn't work, make a weak solution of muriatic acid and water (one part acid to five parts water) and paint this on the tile, then rinse. Then polish with a dry cloth. Wear skin and eye protection when working with acid; and when mixing it, always pour the acid into the water.

And, if all else fails, try this trick, the one that gets that pesky plaster film off wood floors. Mix one tablespoon boiled linseed oil in a bucket of warm water. Mix furiously. It won't mix, but you will distribute the oil a bit in the water. Dip a sponge in this solution, squeeze it nearly dry, and wipe the tiles (or floor). Your hand will feel very oily, but very little oil will get on the tile or floor; there will be enough, indeed, to do its job of grabbing the grout or plaster dust.

Q. I have baseboard heat, and had linoleum ripped up and ceramic tiles put down. The installers laid the tile up to the baseboards, but not under them, where there is a three-quarter to 1-inch space from baseboard bottom to the floor. Would it be OK to extend the ceramic tile completely under the baseboard radiators?

L.W., Beverly

A. It certainly would, because with the tile extended, there still will be a half-inch to three-quarter-inch space between the baseboard and tile. Some space is required for proper air circulation around the baseboards, and the space between the extended tile and baseboards is more than adequate.

Q. I installed ceramic tile on a floor three years ago after taking up some self-stick tile. In humid weather and in high traffic areas, the grout loosens and comes out. I tore up everything down to the plywood under the tile, and a tiler suggested I put down WonderBoard, a concrete board that will be a good underlayment for the tile that will be set with thin-set mortar. He added that if I tried to put the tile down on the plywood (still sticky from the self-sticking tile adhesive), the thin-set will not stick to that sticky adhesive. Now what? Should I take up that sticky adhesive?

S.S., Mansfield

A. Not necesssarily. If you put down the concrete board with plenty of screws, then you can apply the new ceramic tiles with the thin-set. It will be like a mud job, and if the plywood and concrete board are secure, the floor -- and the itles -- will not move excessively.

The grout between the original ceramic tiles may not have loosened because of humidity and high traffic; instead, it might have broken up because it was not heaviy compacted when it was installed. So, when you grout the new tile, make sure it is very thoroughly compacted; you'll be surprised at how much grout or mortar you can get into those joints. Press it in place, and make the joints as narrow as possible.

Q. My 1932 house has two bathrooms with the original tile in a mud job (set in mortar). I have heard of people who can reglaze bathtubs and tile with an epoxy finish. Would this be OK for tile as well? My present tile is black and white on the walls with octagonal white mosaic tiles on the floor. They are getting kind of tired looking, but otherwise are in good shape.

A.S., Belmont

A. Yes, people do reglaze tile, but it is with epoxy, not glazing. But I suggest living with that old tile; some people would covet that wall tile and especially the octagonal floor tiles. So, if you can stand it, leave it as is. Besides, the reglazing with epoxy is also going to cover the grout lines, which will alter the appearance of the tile, making it look like, well, painted tile.

A caller asked where she could find a glue that dries clear, in order to make her ceramic repairs invisible. The Handyman suggested Duco cement, the kind he used a half-century ago on model airplanes, and still does to repair ceramics.

Helen Devereaux of Stoneham called to tell us of another clear glue that she uses. ``I repair pottery and Santas and other ceramic figures,'' she said. ``I use Weldbond, which dries clear.'' She bought it at Round's Hardware in Stoughton.

The Handyman is sure that such a glue is sold at other hardware stores throughout the state.

Q. The ceramic soap dish broke in my bathroom. How can I remove it to replace it, and where can I find old tile fixtures?

ALAN MARGOLIS, Needham

A. If the dish is set in mortar or grout, it may take a lot of chipping to get it off. If it was applied with an adhesive, you might be able to tap a chisel on an edge and pop it off. In either case, chip out the grout bordering the dish first. Once the dish is out, remove all grout and adhesive or anything else.

Then put the replacement dish on with construction adhesive or PhenoSeal adhesive caulk. These adhesives will perform as well as epoxy. Then fill in the edges with grout.

For old tile and fixtures, try General Flooring House of Carpets, Weymouth, 781-337-3600 or 3200. Also, Colonial Floors on Waverly street in Framingham; it has old everything.

Q. Can I dye the grout between ceramic tiles? It is gray now and I would like to make it dark gray.

C.P., Ipswich

A. In theory you can't, but in fact you can. Use a semitransparent stain, the type used to stain outdoor shingles and clapboards. The stain people may throw up their hands in horror, but if you have ever spilled semitransparent stain on concrete, you know it never seems to come off.

And you are going in the right direction, making the grout as dark as practical, which will not show the dirt. For some weird reason, grout makers have come up with all kinds of pastel and designer colors, all light and impossible to keep clean. Light-colored grout on wall tile is OK but the grout on all floor tile should be black.

Another thing you can try is an analine dye, which may do a better job than stain. It is sold in paint stores, specifically Johnson's Paint Store in Boston.

Q. When my sister regrouted ceramic tiles with an acrylic latex caulk, some of the caulk was smeared on the tiles. Acetone did not remove it. What will?

ROBERT DANTONE, Beverly

A. Since it is a latex-based material, try Goof-Off, which is designed for the purpose. If that doesn't work, try Citrus Green or Citrus Clean, sold in supermarkets and hardware stores, or a little chemical paint remover such as Citristrip. Other than that, it is a matter of scraping with a razor-blade scraper.

And, if it really was caulk that was installed between the tiles, it was the wrong material. It should have been grout, which is a Portland cement-based material related to concrete and mortar. If the caulk looks OK and does not get too dirty, it's OK. But ideally the caulk should be removed (very difficult) and real grout inserted, using a sandless grout.

Q. I want to put up wood wainscoting in my bathroom to cover ceramic tile. Can I drill holes in the tile?

K.S., Hull

A. Yes. Use an ordinary steel bit with your power drill. You might have to dig a little starting hole so your drill will not slip when you start drilling.

But you might be able to avoid all that by taking off the tiles. If they were installed with an adhesive, tap a chisel along an edge of the tile and pry off. With luck, they will come off relatively easily.

Q. Is there a way to stain glazed ceramic floor tile? The tiles are OK but I'd like to change the color.

B.W., Billerica

A. No, or at least there's nothing that I know of, because the glaze on ceramic tile is essentially glass, impervious to any kind of a stain. If there is, I'd like to know about it. You can't even paint such a tile floor, for two reasons: Paint does not stick well to glass, and, even if it did stick, it would be quickly scuffed off.

You can paint wall tile fairly well, but that is because it experiences little wear and tear.

Q. How can I determine if linoleum paste contains asbestos? I had vinyl-asbestos tiles installed 30 years ago, and am wondering how I can safely remove them. And, did the asbestos in the tiles contaminate the light-colored glue?

E. Z., Groton

A. I doubt if linoleum paste or any other tile adhesive contains asbestos, and the only way to find out is to check with an asbestos abatement company, or send a sample of the paste to the company for an analysis and an opinion.

As for asbestos in the tiles, it is highly unlikely that any asbestos in the tiles contaminated the glue, because any asbestos fibers are bound in the vinyl and only cutting, sanding, scraping, sawing, breaking, drilling, and otherwise damaging them will release fibers.

Also, many vinyl-asbestos tiles don't contain enough asbestos to be a hazard or come under any regulations. To determine that, have a piece of the tile analyzed by an asbestos abatement company.

Q. The original ceramic tiles on my bathroom floor are 23 years old and badly cracked. Can a floor be reglazed in a similar way as bathtubs are reglazed? If not, what can I do about those cracked tiles?

K.W., Norfolk

A. No. No, ceramic floor tile cannot be refinished or painted or given any other treatment. There is just too much wear and tear on the floor for any finish to remain. Instead, you can have a new layer of ceramic tiles applied to the old, using a thin-set mortar. If you do that, you have to consider that the new floor will be higher than the old and could interfere with doors, which would have to be trimmed.

Or remove the old tiles and apply a new layer of ceramic tiles directly on the underlying plywood, which is the best solution. Another alternative is to take off the ceramic tiles, smooth out the plywood floor and apply sheet vinyl or vinyl tiles.

Whether you add tiles or scrape off the old, you must remove the toilet, then reinstall it on the new floor.

Q. The 13- by 13-inch ceramic tiles in my kitchen floor have developed a few chips that have turned black. How can I repair them?

JOHN BROOKS, North Reading

A. Repair is impossible; replacement is the only way to get rid of them. However, you may not have to go that far. You can disguise those chips by dabbing them with an oil-based indoor-outdoor enamel, or appliance touchup paint. Put several thin coats on; this will thicken the paint and help fill the chip.

Such painted chips may not last very long. Whenever the paint wears off, dab them again. You might have trouble finding a color match to the tile, but it's worth a try.

Q. I plan to put self-stick tiles on my concrete basement floor. At times, especially in summer, it is damp. Would the self-stick tiles tend to pop from this dampness? Is there a good alternative?

G.P., Littleton, Mass.

A. The tiles may pop from the dampness, but more likely from water vapor coming up through the concrete from the ground below. And that is not likely to happen for many years.

There is a taboo against resilient tiles and sheet vinyl on basement floors because they can trap water vapor under the material, which then condenses into water. The tiles are better than sheet vinyl because tiles, with many joints, will allow water vapor to go up between the them rather than directly under them. So, go ahead and see what happens.

A viable alternative is to put down indoor-outdoor carpeting, which allows the water vapor to come up through the carpeting into the room, where it can be ventilated away. And, you can handle that summer dampness by ventilating the basement. Keep the windows open all summer long.

Q. The self-stick tiles came off my dining room hardwood floor easily, but left a thin, sticky layer. How can I remove that sticky stuff before sanding and refinishing the hardwood?

RON SUMMIT, Newburyport

A. Try a little heat, as from a hair dryer, and scrape with a wide, stiff putty knife or wide chisel. The heat may make the adhesive even more gummy, making it tougher to remove. So, if that doesn't work, lay a cloth bag filled with ice cubes on the floor, then scrape. The cold will make the adhesive brittle and more easily scraped. If that too doesn't work, you will have to resort to chemical paint remover.

These are tedious tasks, but are necessary because sanding any excess adhesive will gum up reams of expensive sandpaper.

Q. I'm installing self-stick tiles on my the plywood kitchen floor. There is a little rise in the plywood. Will this be OK? In one area 3 by 3 feet, the old adhesive is gummy. How can I get it off? It gums up when I scrape it.

PAUL EVANS, Milton

A. At least the gummy area is not big. Try this: Put a bunch of ice cubes on that area and wait until the adhesive becomes brittle. Then scrape it off with a wide chisel.

As for the rise in the plywood: You can put the tiles down. Being resilient (flexible), they will follow the contours of the plywood rise; ceramic tiles might not fare so well. If there is a slight lip where plywood panels butt together, I suggest you sand it to eliminate the lip. If you put a tile over the lip, it would break, eventually, especially when stepped on.

Q. We're planning to install a new ceramic-tile floor, but our biggest challenge, I think, is how to take up the old ceramic tiles, some of which are cracked. The tiles are on plywood.

W.G., Somerville

A. All you can do is try, and hope springs eternal, along with hard work. The way to go is to slip a chisel under a tile edge and push, and pry up.

If the tiles are set with an adhesive, they will pop up with a slight prying, usually in one piece. With luck, they will come up easy as pie.

If the tiles were set with thin-set mortar, do the same, but you will need more tapping with chisel and hammer, and the tiles are likely to break up in many pieces. That's the name of the game; you just scrape and scrape until you're through.

The plywood must be free of all adhesive or thin-set for new tiles to go down. You can set the new tiles in thin-set, which will hold better than the adhesive, or use adhesive. I suggest you choose a small tile; no larger than 6 by 6 or 8 by 8 inches. The reason for that is if the plywood is the least bit uneven, or there is even a slight bump where plywood panels meet, large tiles will tend to rock when walked on, and rocking tiles are sure to crack.

The only way large tiles (12 by 12 inches and larger) will work well is if they are installed in a bed of mortar, and that project is for a professional.

Q. There is a stain on my ceramic floor tiles in the kitchen. It has dulled the shine, but is not sticky to the touch. It looks like dried oil. How can I clean it? I tried ammonia, Goo-Gone, vinegar, and paint thinner without success. The tiles are glazed, with a good, but not a high, shine.

M.L.M., Sharon

A. If none of the above moved the stain, I think it is because they were not left on the tile long enough to soften it. You could try again with any of those solutions, including a strong detergent solution, but leave them on the stain for 2 minutes or more, being careful that they don't evaporate. Then scrub and wipe up with a dry cloth. Or, apply one of the solutions, leave for a minute or so, then scrape with a razor-blade glass scraper. Since the glaze is essentially glass, the scraping won't hurt it, unless you get carried away.

Q. Some of the ceramic tiles popped off the walls of a basement bathroom. I plan to put them back, and was thinking of filing down the little knobs or ears on each side of the tile, which I think are interfering with proper adhesion. Would this make the tiles hold better when I put them back? I would also like to put back a soap dish that popped when someone used it as a grab bar. Would tile adhesive work to put it back, or will grout? The tiles were originally set with some kind of dark yellow mastic.

M.G.V., Wayland

A. The little knobs are called ears, and keep the tiles positioned properly; they have nothing to do with the tiles popping. What probably happened is that not enough adhesive was used. So, scrape off as much mastic from the wall and the back of the tile as possible, and put the tiles back with a bit more mastic, but not so much that it oozes between the tiles when you press them in place. If mastic oozes between the tiles, it is difficult to remove, but it must be removed so grout can be inserted.

As for the soap dish, scrape off the mastic from all surfaces and install it with a thin-set mortar.

Q. I just can't keep grout in the joint between the tile wall and the bathtub, which is about an eighth of an inch wide. It always seems to wash away. How can I make it more permanent, or at least last longer than a few weeks or months. I keep putting in new grout, using a damp sponge to fill the cavity.

R.T., Arlington

A. That damp sponge technique is a dead giveway. You simply are not compacting the grout enough. Grout must be heavily inserted to prevent air pockets, which cause early failure. Also, be sure to chip or gouge out every bit of grout, to the full width and full depth of the joint. And, in order to get as much grout in as practicable, buy a sandless grout. Instead of a damp sponge, use a squeegee to press it in. And press it in; avoid excessive rubbing back and forth with the squeeqee. That eighth-of-an-inch gap is a little narrow, but if it is as deep as the tile is thick, the grout will hold.

Q. Is there a place that I can find old and old-fashioned ceramic tile to match the tile in my old house? I have to replace some of my tile and I don't want to take it all off and put in all new, at considerable expense.

J.S., Woburn

A. Yes, there is; in fact, several. Try one of these: 1. General Flooring House of Carpets, 208 Main St., Route 18, Weymouth, (617) 337-3600 or 337-3200. 2. Vermont Salvage in Manchester, N.H., and White River Junction, Vt. It has old tile and metal ceiling tile, marble and old mantels and door hardware. 3. Colonial Floors on Waverly street in Framingham. Old everything.

Q. My outdoor porch -- a concrete slab -- was enclosed, using a lot of sliders. We took up an indoor-outdoor carpet because it got wet, but discovered a gummy glue material under the carpet. It doesn't come up very easily. We tried painting a small area, but it took five to six days to dry. How can we get that rubbery stuff off, and what would be best to put on the floor? Would ceramic tile work?

J.K., Pelham

A. It sure would, and the Handyman appreciates your mentioning it, because he had a lot of ideas but not ceramic tile. Put it down with a thin-set mortar. You won't have to remove the gummy stuff if you use thin-set. You could also use area rugs on the tile.

The only other material I suggest is a concrete stain, but the gummy stuff has to be removed first. Remove it with chemical paint remover.

Q. What works best to clean ceramic tile? I have some gray tile that did shine once. I washed it with Spic and Span and water, and it is dull now.

P.M., Braintree

A. Next time you wash, use plain water. When it dries, polish the tile with a dry cloth. A power buffer will also do nicely, but you may find that you don't need power.

Q. I just moved into an apartment that has a shower stall with 12 inches of wall space between the top of the stall and ceiling. The bare wall space has a peeling paint problem. Can I put vinyl tiles on that wall?

J.S., Stoneham

A. Absolutely, and the landlord should be thankful that you corrected a long-standing problem.

Use the peel-and-stick self-adhesive tiles. The 12-by 12-inch tiles will fit right in the space.

Be sure to scrape and sand off any peeling paint before you stick on the tiles.

Q. The ceramic tiles around the edges of my concrete floor cracked. They are 8 by 8 inches and installed with thin-set mortar. Why did they break? How can I chip them out? The tiles are several years old, and I am not sure If I can find matching replacements. Are there any dealers of old tile?

ARNOLD WINSTON, Cohasset

A. Now why would border tiles like that crack? I can only guess that if there are heating elements along the border, the extra heat might have caused excessive expansion and contraction of the tiles, and that can lead to cracks.

Chip out the old tiles with a cold chisel and hammer. Use a mason's hammer, which is heavier than a standard hammer. You need extra oomph behind the chisel in chipping out old mortar and tiles.

You might be able to get a match for your old tiles at one of these places, which specialize in old tile: General Flooring House of Carpets, 208 Main St., Route 18, Weymouth, telephone 337-3200; Vermont Salvage in Manchester, N.H., and White River Junction, Vt.; Colonial Floors on Waverly Street in Framingham.

If you can't find matching tiles, consider creating a distinctive border by putting in new tiles of a contrasting color in the entire border.

Q. I am buying an 1897 house. The tiler proposed laying new tile over the old tile on a floor set in a mud job. Would this work, or would it be too heavy?

FRED LEVY, Cambridge

A. Most houses, even old ones, can take a lot of weight, and two layers of tile in a mud job (mortar) is usually not too heavy for the floor, which probably already has a subfloor and top floor under the original mud, making it capable of holding the extra weight. If the original mortar is reinforced with steel mesh, it helps make the floor withstand greater weight.

One hazard: If the extra mortar and tiles are too heavy, and now your floor is sagging or jiggling or flexing, it would have to be reinforced by adding extra joists under it.

The only other way is to remove the mortar and tile, lay down a new bed of mortar, and install the tiles. This latter way will be lighter in weight and will not raise the floor, but it is a lot of work taking up the mortar and tiles -- and disposing of them.

Q. About half of the ceramic tiles on my tub surround fell off, because the plywood wall had warped. I fixed the warp and scraped the old glue off the tiles. How can I get the tiles to stay? The plywood is over plasterboard.

BARRY STEARNS, Waltham

A. The tiles failed because of the warp, and also because the surface they were applied to is wood. The plywood is not stable; it will expand and contract with intake and loss of moisture. This movement, in addition to the warp, worked off the tiles. Use a little more adhesive when putting the tiles back.

This happened to the handyman years ago; he simply used more adhesive in resetting the tiles, and they've held for years. Ideally, it is better to put ceramic tiles on cement board (WonderBoard is one brand), which is really concrete refinorced with fiberglass. But you don't have to do this.

Q. Some of the slate tiles on a pine floor are loose, and I would like to remove them all and restore the pine floor. How can I remove them, and how can I remove the gray cement under the slate?

MAUREEN BERNSEE, Lexington

A. To remove the intact tiles, insert a chisel under an edge and pry up; as you drive the chisel under the edge, the tiles are likely to pop. If they don't, a little prying will pop them. If not, you may have to break up the tiles but I doubt that will be necessary. To take up the gray cement, which sounds like mortar, scrape and scrape and scrape some more. If the ``cement'' is an adhesive, chemical paint remover should work on it.

Q. I had ceramic tile laid in a house in Florida, and it's great except when the sun hits it. It looks stained white along the joints. I tried scrubbing with vinegar without success.

FRED PARSHLEY, Watertown

A. The grout between the tiles was smeared on the tiles during installation. No scrubbing will remove it. To remove it, mix one part muriatic acid with one part water (always pour acid into water), and paint it on the joints. When the grout stops fizzing, rinse. Vinegar is not strong enough an acid for the grout.

Q. I took off tiles in a bathroom when I redid the room, and plan to put them back up. I soaked them in gasoline to soften the adhesive so I could scrape it off. Now, when I'm ready to put them back up, they are dry but still smell of gasoline. How can I get rid of that odor?

BILL MAGNUSSON, Malden

A. Soak them for an hour or so in a strong solution of Spic and Span and Water. Rinse and let dry. Or, make the solution of baking soda and water. Either should work.

Q. The rose-colored, unglazed, 12-inch ceramic tile on my floor has developed a gray stain around the edges of each tile. It didn't show from the start, but started about two weeks ago. What is it and how can I get rid of it? The tile man said he didn't use grout film cleaner when the tiles were installed, and, if it wasn't used then, it's too late.

M.R., Hanover

A. It's never too late. The graying might be a film of grout, although, if it is, it would appear immediately. For starters, make a mix of one part muriatic acid and one part water (always pour the acid carefully into the water to prevent splashing), and apply this to the floor. If the gray on the tile fizzes up, it is, indeed, a grout film and the acid will take care of it. If this treatment doesn't clean off the gray, you can resort to an old remedy: Wet the tile with paint thinner and scrub with steel wool until the gray is gone.

Q. Can I paint ceramic wall tile? If so, with what?

R.G., Dorchester

A. Yes, but . . . I say that because it may be iffy, and painted ceramic tile will look like painted ceramic tile if you also paint the grout.

Anyhow, sand the tile to reduce gloss and rough up the surface. Apply a latex enamel undercoater and finish with an oil-based indoor-outdoor enamel. With luck, it will last for years. Do not try to paint ceramic floor tile; there is simply too much wear and tear on a floor for the paint to last very long.

Q. White mosaic tiles on my shower floor are getting all scummy, and the grout is really dirty. How can I clean the tile and keep the grout clean? Can I put new tiles on top?

M.J., Acton

A. There are a million products out there for cleaning scummy tiles; three are paint thinner, kerosene, and Soft Scrub. Straight bleach will also dissolve that scum, and might also clean the grout. Rinse off anything you use on the floor.

You can put new tiles over the old, using a thin-set mortar, but it has to be the mosaic (small, 1-by-1 inch and 1-by-2 inches) tiles because of the compound slope of the shower floor. If you put in new tiles, use a black grout; it will not show the dirt. Anything much lighter than black will show the dirt and it is difficult if not impossible to keep it clean.

If you do get the grout clean to your satisifaction, apply a masonry or tile sealer once a year to make the grout water resistant and therefore dirt resistant.

Q. I have some loose tiles in a shower floor. They are intact, but I can feel them loose when I shower. How can I reglue them?

G.N., Boston

A. Pick up the tiles, scrape off any grout from their edges and also scrape off any adhesive or mortar on their backs, and on the floor where the tiles were. Reglue the tiles with Phenoseal, a phenolic vinyl adhesive caulk which works wonderfully, or thin-set mortar, which works equally well. Regrout the joints and you're in buisness.

Q. I moved into a house with white ceramic tile and very dirty grout. How can I clean it or color it an even color?

CAROL ALLEN, Milford

A. Try cleaning it with bleach and water, and scrubbing with a toothbrush. If it does not come clean, apply Grout Colorant, sold in tile stores. Or, paint it with a dark-gray semitransparent stain; the type that goes on clapboards or shingles. It is not designed for grout, but it will stick quite well. The dark gray will not show the dirt and presents a nice contrast to the white tile.

You can do the same on floor tile, but don't bother trying to clean the grout. It never comes clean, and is better off stained dark.

Q. The 12-inch-square ceramic tile has been on my kitchen for five years. Now, five tiles have hairline cracks; it looks like crazing in the glaze. The tiles were put over 1/2-inch plywood atop a subfloor with thin-set mortar. Can they be reglazed, or do they need replacing?

MARY GUERRIERO, Westwood

A. They cannot be reglazed, but they don't need replacing, either, except for cosmetic reasons. If you can tolerate how they look, forget about them. The crazing (spider-web-type cracks in the glaze) is superficial, does not go through the tile, and was caused by a blow to the tile or a defect.

If you really want to replace them, you have to chip out the mortar and break up the tile in order to chip it out altogether. Be sure you find matching tile before chipping. With the tile removed, chip out any mortar remaining on the floor. Install a new tile with thin-set mortar or an adhesive caulk, and regrout.

Q. I have some quarry tile on my kitchen and entry floor, and it's the worst thing I have had in my life. The tile is stained, and the grout is many different colors. I sanded the grout to reveal fresh material, then sealed it. Can I paint it? There is something on the tiles themselves, but I don't know what. Is there a way to make the tile a little more resistant to stains?

EILEEN RUDY, Holliston

A. I would not suggest painting grout, but there are two things you can try tht might be just as good or better. A tile colorer and sealer called Grout Colorant, sold in tile stores. The other is to use a semitransparent stain, like the stain used on house exteriors. This stain is not designed for concrete, masonry or grout, but is worth trying. Colors are limited.

As for the tiles themselves, no one knows what's on there now, so it would be risky to apply anything else, which could make it worse.

If you can get everything off the tiles by rubbing with steel wool and paint thinner, then you can try Future, an acrylic finish designed for linoleum, but it can work also on quarry tiles. No guarantees.

Q. I read your reference to hard, smooth ceiling tiles, to cover an old, peeling bathroom ceiling, which you said are easy to keep clean. I looked around and found nothing like that. What are you talking about?

DAVID HELMER, New Orleans, La.

A. I am talking about ceiling tiles that are hard (not soft as many fiber tiles), smooth (not acoustic tiles, those with holes or fissures). They come 12 by 12 inches, sometimes 12 by 24 inches, and can be put up with adhesive. They are sold in lumber and building supply stores; even the chains like Home Depot should carry them. Armstrong, a big name in ceiling tiles, makes them, among others.

I put them in one of my bathrooms years ago; they not only are hard and smooth and washable, but the paint, which gives the tiles their hardness, does not peel.

Q. How can I hang things on a ceramic tile wall?

BEN SIMON, Somerville

A. You can hang things on a ceramic tile floor by drilling small holes through the tile and installing a round-headed screw into a stud, or if there is no stud, inserting a molly bolt. Hang things on these protruding screw or bolt heads.

It is relatively easy to drill holes in ceramic tile. You can buy a special spade bit for drilling ceramic, and glass, for that matter. Do it slowly. And drill a scrap piece of tile to see if you can do it. That will also give you a little practice before you go to the real thing.

Q. My quarry tile is 18 years old. I put on a polish, but some of it peeled. I can't chip it off so I tried polishing it with Armstrong's Shine Keeper; now some parts are shiny and some are not. What can I do to make the whole floor consistent?

KATHY MILMOE, Cambridge

A. Admittedly quarry tile is good looking, but being unglazed it is extremely absorbent, and will take up all kinds of stains, which are difficult to remove. So ``they'' suggest putting all kinds of stuff on them to make them washable and stain-resistant. Many such applications either peel or create white spots.

So, my suggestions are iffy at best. For starters, put on another coat of Shine Keeper to see if that makes the shine consistent. Do this first in an obscure or small area to see if it works. Or, apply a thin coat of Future to an obscure area to see what it will do; it should give a fair, consistent shine, but it also might cause white spots to appear, especially if applied to another sealer. But if no spots appear and the shine is consistent, then do the entire floor.

If Future doesn't work, there is no choice but to remove everything. Dip steel wool in paint thinner and scrub each tile thoroughly. Or, use chemical paint remover, scrubbing with steel wool. Wear skin and eye proteciton when using paint remover, and use lots of ventilation as well. Use one of the milder paint removers such as CitriStrip.

If you ever get down to the unsealed tile, then you can apply a coat of Future, which will give a shine, or masonry sealer, which will provide no shine but help make the tile water and stain resistant.

If you have the opportunity to re-floor, use glazed ceramic tile; it comes in a high or low shine. The handyman has gotten into big trouble in the past for his suggestions on treating quarry tile, so he gives you his caveat: No guarantees that these treatments will work or not make the tile worse looking.

Q. Three of my 3- by 6-inch plain white tiles on the first row at the end of the tub have cracked, in an arch across all three tiles. The faces of other tiles are crazing and the craze lines are black. I found three tiles that are reasonably close to the originals. How can I remove the old tile and put in the new. The tiles are on mortar set on wire lath. How can I clean the black craze lines? And, incidentally, why did the three tiles crack in that arc shape, spanning all three tiles? There is no sign of moisture in that area.

J.V., Hingham

A. The tiles cracked because of tension; the wall moved a bit, and the tiles, being in mortar, couldn't move, resulting in the crack. If the tiles were set with an adhesive, they might have been able to move with the movement of the wall, but there's no guarantee they wouldn't crack, even in that case.

You will have to chip out the tiles with a cold chisel and hammer; be careful, those tile shards are very sharp. Then chip off some of the mortar so that when you put in ts with a thin-set mortar, or a tile adhesive, or an adhesive caulk called Pheno-Seal. Then fill the joints with grout.

As for the craze lines, treat them with a bleach-and-water solution; if the black is mildew, they should clean up nicely. If they don't clean up, black is dirt and a detergent is needed, and that might not lighten them much either. If the bleach solution does not work, live with the black craze lines. he new tiles, they will line up with the original tiles. You can put in the new tile

Q. have a built-in tiled seat in my tiled shower stall with a nice bull-nosed edge. Trouble is, some of the bull-noses have came loose. Even more trouble, they later tightened up and are no longer loose. What can I do in case they become loose again? If I reset them, should I use caulking between the tiles, or grout?

KATHY STARK, Newtown, Conn.

A. I suspect the tiles are set in a mud job, meaning they are set in mortar rather than with adhesive. They may have tightened up so they do not move perceptively, but they are still loose. And if they did loosen originally, some of the grout might be broken up.

As long as they are tight to the feel, you can probably live with them. But you can do this now or when they do loosen up more. Lift them carefully, scrape off mortar from the backs of the bull noses and some off the surface they were mortared to. Scrape off any grout remaining on the sides of the bull noses and any on the original sutar that will hold wonderfully, and can be applied in thin layers. If the replaced bull noses set higher than their neighbors, remove more of the mortar surface. The replaced bull noses should line up with their neighbors.

After a day or so, apply grout to the joints. If the joints are very narrow ( 1/8 inch or narrower), apply sandless grout. If the joints are wider, install sanded grout. To answer one of your questions, do not use caulking between the tiles; grout works much better.

Q. You said I could put vinyl tiles over linoleum. Can I put vinyl tiles over ceramic tiles?

VIRGINIA O'BRIEN, Scituate

A. Sure you can, but you will regret it because the vinyl will settle on the ceramic tiles, which will ghost through the vinyl and show. Besides, why cover ceramic tiles: OK if it is because of color, not OK if the old ceramic is dirty, or rather the grout is dirty. You can clean the grout and seal it with a tile sealer so the tiles will resist dirt. To clean the grout, bleach and a detergent may help. There are a gazillion cleaners on the market for this purpose, and I am not convinced that any will work. So, instead of trying to clean the grout, scrape off the top layer, revealing new grout. Then seal.

Q. The original white ceramic tile in my 70-year-old house is in good shape, except it is crackled in the glaze. The crackle lines are black, and no bleach or anything else will workfor me. I tried Tilex, straight bleach, and acid, on separate occasions (I never combnine these materials), all without success. What will clean those crackle marks?

JANE WEISS, Dedham

A. Those crackle marks are called crazing, and you may have to live with them. But as a final try, wash the tile with Soft Scrub or Simple Green. Flow on either material and let it sit on the tile for 15 minutes or longer. Then scrub and rinse. If this improves things, fine; if not, try KRC-7 Porcelain Cleaner, sold in plumbing supply stores. Good for dirty grout, too.

Q. I like the idea of using the hard-faced ceiling tiles you mentioned recently for my bathroom. I can keep them clean and paint them when I feel like it. But where can I find them? Home Depot was no help.

C.T., Reading

A. You are not alone. There were several inquiries from callers who could not find them. I assumed they still existed because I put them in my own bathroom several years ago. If they are no longer made, it's a pity; they did yeoman service. So, your best bet is to call Armstrong World Industries Inc. at 717-397-0611 to determine if they exist and where you can buy them.

Q. I am retiling around the tub and backsplash. I am wondering how I can remove the old tiles? They are set on concrete board and none is loose that I know of.

GAIL RIEP, Acton

Q. How easy or difficult the tiles will be to remove depends on how they are set on the concrete board. If they are set with adhesive, it should be easy. Insert a chisel at the edge of a tile, tap with a hammer and it should pop off, or come off with a litle more tapping. Now, you can scrape off any residual adhesive and put up the new tiles with the same type of tile adhesive. If the tiles are set with a thin-set mortar, it will be tougher. Tiles set with thin-set on concrete board is akin to a mud job; very strong and difficult to demolish. But you can still try the same technique as with tiles installed with adhesive. Slip a chisel under an edge and tap lightly. If the tile does not pop, you will have to keep tapping and prying, which may break up the tile; then each piece must be chiseled off. Once removed, scrape off as much of the thin-set as possible, then install the new tiles with thin-set. You have to scrape all the old thin-set from the concrete board so the tiles will lie flat and even.