Q: In the apartment I recently purchased there is an old-fashioned bathroom with an enormous tub. The previous owner painted this tub and it is now flaking. I would like to repaint it in a new color. Can you tell me how to do this?

A: First you will have to get all the old paint off. For this I would suggest a semipaste-type paint remover, used according to the directions on the can. Try to avoid washing the material down the drain because this may clog it. Then scrub the tub thoroughly with a strong cleanser, rinse several times with lots of water, and allow to dry thoroughly. They buy a two-part epoxy paint in the color of your choice and apply one or two coats, depending on the directions. Remember that careful cleaning and preparation of the surface (as described on the can) is very important, so be careful about doing a thorough job.

Q: I live in a ranch house built on a slab, and this winter for the first time we are having a problem: After every heavy rain the windows sweat so much that they actually drip; the front door is soaking wet, and the ceiling is wet in spots -- especially around every electrical fixture in the ceiling. What can we do about this situation?

A: Two possibilities occur to me from your description: You have a roof leak somewhere up there that you are not aware of, which is not only letting moisture in, it is also adding to the humidity inside the house; the other, which I think is more likely, is that you have a condensation problem in the attic, coupled with excessive humidity inside the house. The condensation (in the attic) may be caused by a lack of adequate ventilation above the insulation (up near the peaks, or along the ridge), and this, combined with excessive humidity downstairs, could be causing the combination of problems you have. Exhaust fans in the kitchen and bathrooms will help if they are used whenever water is being used in these rooms, but attic ventilation, if you don't have any, or vents that are large enough, are of paramount importance.

Q: We have baseboard heating units and over the past several years the walls and ceilings above and alongside these units have become darkened and soiled looking. I am planning to paint these rooms, but would like to correct the situation first. We have tried screen mesh to trap the dust, but this hasn't helped. What do you suggest?

A: You are right in assuming the problem is dust, but a screen won't help. You have to periodically clean the dust from around and under the fins and piping of your radiators. It accumulates there, then gets carried up onto the walls and ceiling when the heat is on because hot air rises.

Q: We have a cathedral ceiling in our living room that is made of Sheetrock covered with a light coat of plaster, then painted. After 20 years the nailheads have loosened and are poking through the paint and plaster. Before painting we pounded the nails back in and then spackled over them, but in a short time the nails reappeared and now look as bad as ever. Is there a remedy you can suggest?

A: Since the nails worked loose once, just driving them back in will not make them hold any better -- especially on an overhead surface. This time, after you drive them back in, drive an additional nail in a couple of inches away from the one that worked loose, but use a large-head ringed or annular-threaded nail of the type that is made for use with drywall. These nails will not pop out.Recess them only slightly, then spackle as before. Also, when you drive the old nails in, either drive them far enough so they go into fresh wood, or pull them out entirely after the new ones are in place. The new ones should be long enough to go through the Sheetrock and penetrate the wood behind it by at least 1 inch.