Question - 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 tile were put over 1/2-inch plywood over a subfloor with thin-set mortar. Can they be reglazed, or do they need replacing?

- Mary Guerriero, Westwood, Mass.

Answer - 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.

Question - I bought a house with a strong odor of stale smoke. I cleaned the carpet and that seems OK, but the smell is coming from the paneling. Someone suggested washing the paneling with ammonia and water. I also bought water-based polyurehane varnish, hoping to seal in the odor. Anything else I can do?

- Mike, from Medfield, Mass.

Answer - The ammonia and water sounds OK to do because washing the paneling will do the most good. But instead, I suggest a standard solution of Spic and Span and water; I think it is still one of the better cleaners on the market. Wash the paneling thoroughly; the finish should not be affected, although it might become dull. Rinse. If that does it, you will not have to seal it.

If you have to seal the paneling, do not use water-based polyurethane; it is incompatible with the oil-based finish on the paneling. One coat of a satin finish should do it; before coating the paneling, sand it lightly to roughen the finish. The paneling will look terrible after that sanding, but after you wipe it with a damp cloth and let it dry, the new finish should look very good. I think brushing is best.

Another good cleaner is paint thinner. Use lots of ventilation when working with it.

Question - I am having a new roof installed. I know I have to have two layers of shingles on there now removed, but one man said I didn't need an Ice & Water Shield because I don't have gutters. One man said he would put in a ridge vent, another said I didn't need one. Now I'm all confused.

- Gina Villa, Milford, Mass.

Answer - You don't need an Ice & Water Shield because you don't have gutters? Wrong. You don't need a ridge vent? Wrong, maybe. OK, let's explain. An Ice & Water Shield is a strip of rubberized material 3 feet wide that is put on the eave edge of a roof, under the shingles. It is designed to prevent water dammed by an ice dam from backing up under the shingles and into the house. An Ice & Water shield does not prevent ice dams. It is routinely installed when a new roof is put on, because it is the state of the art in roofing, and is easy and inexpensive to do.

The claim that you don't need an Ice & Water Shield because you don't have gutters is wrong, because ice dams can form with or without gutters.

After all that agony, have the Ice & Water Shield installed.

As for the ridge vent. You may not need one if your attic is properly ventilated, but you do if it is not. And even if it is well ventilated, a ridge vent is a good idea, to help air escape from the attic. A ridge vent is usually done in conjunction with soffit vents (vents in the underside of the roof overhang), and the resulting ventilation will help keep the attic cool in summer and help keep it dry in the winter, two important factors in the health of a house.

After all that agony, put in the ridge vent; it is easiest to install when the roof is being reshingled. A ridge vent costs about $10 per foot installed, but is worth it.

Question - When I cleaned up a white marble mantel with soap and water, it continued to smell like heating oil. How can I get rid of that odor?

- George Peresman, Newburyport, Mass.

Answer - Marble is absorbant, so you must use an absorbant material to pull out the oil, and you must use a solvent to activate the oil in the marble. So, dampen the marble with paint thinner, and sprinkle baking soda over it, at least half an inch thick. Let it sit for an hour (you may see the baking soda turn yellow, which means it is absorbing the oil). Sweep it up and throw it away. Repeat as necessary.

Repetition is the secret to success. And rest assured it will work. Other absorbants you can use are Speedy Dry and cat litter. Both are absorbant clays.