Protect yourself, your home from dust

Q. I plan to tape a lot of drywall joints and will have to sand the joint compound afterward. I know it will raise a lot of dust, and wonder how I can protect my lungs and also keep household dust down. Can you help?

A. You can protect yourself by wearing an inexpensive dust mask or particulate mask, sold at most home centers. Be sure and choose masks with a rating of N95 or higher stamped on them; masks with this rating are excellent for sanding drywall joints, wood, sawing, sweeping dust-raising surfaces, and so forth. (Some people with allergies also wear them when mowing grass or weeding.)

You should also be sure that the mask has two straps, one near the bottom and one near the top. Most masks have a flexible strip across the nose that can be shaped to the face for a tighter fit. Some masks also have a breathe-out vent that makes them more comfortable to wear.

While masks of this type are fine for nontoxic dust, they are not suitable for filtering toxic vapors or working with dangerous materials such as asbestos or lead paint; these require a special respirator mask.

You can help keep dust from spreading throughout the house by sealing off the room where you are working. Tape plastic sheeting over any open entries. Also cover any furniture in the room with plastic sheets.

Many modern sanding tools also have dust-collection ability, so that much of the dust produced by sanding can be sucked up immediately. Some finishing sanders suitable for sanding drywall joints can be equipped with perforated sandpaper and hooked up to a shop vacuum.

If you don’t have one of these tools, have someone hold the intake hose of a vacuum near where you are sanding. The vacuum will pick up much of the flying dust.

Q. I recently installed polyethylene pipe insulation on my iron cold-water pipes to keep condensation from dripping on the basement floor. Can this cause the pipes to corrode?

A. If moisture gets trapped under the insulation, it could cause corrosion, especially on iron pipes. To help prevent this from happening, make sure the pipes are clean and completely dry before installing the insulation.

Also make sure the insulation is a good fit for the pipes. Many do-it-yourselfers use tubular polyethylene insulation, sold in sections about 3 feet long. The tubes are slit lengthwise so they can be slipped over the pipe.

Lock the slit joint tightly and try to avoid gaps where moisture could take hold. You might also want to remove a section of insulation occasionally to make sure the pipes are still dry.

Many experts recommend insulating both cold-water and hot-water pipes, the former to prevent condensation and the latter to help keep hot water from cooling in the pipes.

Polyethylene insulation should be kept a safe distance from any surface that might create a fire hazard, such as the flue on gas water heaters. If the insulation is kept at least 10 inches away from heat, it should be safe.

I have insulated some of my cold-water pipes, but I think a dehumidifier is more effective in preventing condensation on pipes or other cold surfaces, including metal ducts and even walls and floors. It is also difficult to effectively insulate pipe fittings such as valves, elbows and unions.

A dehumidifier costs more to buy and operate, but the results in damp basements can make it worthwhile.

Q. The water-based paint in our bathroom never seems to last more than five years before it begins to crack and peel. There is no vent fan in the bath, but it is always ventilated by an open window or door. Is there paint that will last longer?

A. You should be able to get better results with a special kitchen-and-bath paint. These paints are better able to withstand the tough high-moisture conditions in kitchens and baths. You can buy special kitchen-and-bath paint at most paint stores and home centers. Most of these paints are also designed to help prevent formation of mildew or mold on paint.

If possible, you should also install a ventilating fan that can expel moisture to the outside before it has a chance to damage the paint.