Burnishing is a common problem with paint

Q. We read your article about drywall screws and thought you might be able to help us. Our son-in-law helped us with our basement. First, we put on two coats of gray Drylock on the outside wall of the basement. Studs were installed all around. He placed insulation between the studs and then put up the wallboard with screws. I painted the wall burgundy with Behr. Unfortunately, five coats were required to cover properly. Now every time someone touches the painted wall with a hand or bumps it, the wall shows a dust residue. I asked both Home Depot and Behr, and they have no answer.

Also, and most important, all the screws in the wallboard are popping out. It looks terrible, and we are stumped. We have not finished the flooring or ceiling because we don’t know what to do about the screw pops. Do you think he used the wrong kind of screw? We thought it might be dampness making them pop, but it’s on all four walls. Are we going to have to tear down all that wallboard and start over?

A. The dust residue showing on the photo is coming from the burgundy paint. It’s a common problem, known as burnishing, which is typical with all deep colors in flat, matte or eggshell finish. With these colors, you should use a higher sheen, like a high gloss.

To stop the dusting, you can apply a coat of the same paint color in high gloss, use a water-based urethane or a faux-finish clear-glaze coating that will dry with a flatter look than the water-based urethane. But be aware that any of these treatments will affect the color of the walls.

As to the screw pops, assuming your son-in-law used drywall screws and set them so their heads are slightly dimpled, it sounds as if the studs had high-moisture content and the screws popped out as they dried. If that is the case, the compound on their heads can be removed and the screws re-driven with a slight dimple to accommodate the new compound.

Are your basement foundation walls made of concrete blocks or poured concrete? If concrete blocks, make absolutely sure the grade around the foundation is sloping away to prevent any moisture from penetrating the blocks, as any moisture will now be trapped within the blocks’ cores now that you have applied a waterproof coating on their inside surfaces. This could be quite serious.

Q. When our house was built in 1954, a Moncrief furnace was installed. Our house has six rooms and a full basement game room. Each year, we consider replacing the furnace, but it continues to run well. Several years ago, we replaced the motor and a thermocouple. The plenum appears to be in good shape. We have checked it with a carbon-monoxide meter, with no bad results. Would you advise replacing a 56-year-old furnace with no major problems?

A. It’s only a matter of time before the furnace will become tenuous; heat exchangers have an average life that is much shorter than 56 years — and a furnace that old is unlikely to be energy efficient.

But you should seriously consider having an energy audit before replacing the furnace, because a 1954 house is also likely to be energy inefficient. If you made the improvements that the audit will recommend, you will need a much smaller furnace, thus not only saving on its cost but also on your energy consumption. The capital improvements should pay off in time if you are planning to stay in the house for many years.

Q. My first-floor toilet started leaking at the floor level. I had someone replace the wax seal and the gasket. It still leaked, so I caulked around the base of the toilet. That solved the problem, but now every time I flush, about a whiskey glass of clean water comes up the sink drain, and it takes four to six hours for it to drain. Once in a while, I get a sewer smell. The tub drain is fine. The house is 100 years old. We bought it in 1995, but the bathroom is newer than that.

A. Normally, backup should take place in the lowest drain, which would be the tub. Assuming the sink is in the same bathroom, it sounds as if its drain is tied into the main sewer line past the toilet drain, while the tub drain ties in past the sink drain and there is a clog in the main sewer drain between where the sink and the tub tie in. Sometimes the toilet may be vented to the sink’s line. When you caulked the base of the toilet, and you flushed it, you forced the water to back up the sink waste into the sink. The toilet waste line will need to be snaked clean.

Q. I have a room in my 1940s Cape Cod home that has wallpaper buried under many layers of paint. I would like to remove the wallpaper before repainting the room again and am wondering what you recommend as the most effective method? Should I wait until a humid summer day?

A. The removal method depends on the type of wallpaper. But in your case, since the wallpaper is covered with many layers of paint, you will probably have to use the same method as if the wallpaper were nonporous, unless the wallpaper is of the type that is dry-strippable. In that case, loosen the top of each strip with a putty knife or screwdriver, and peel it off using two hands and a down motion close to the wall in order to avoid damaging the substrate. Otherwise, you can use a wallpaper-scraping tool — like the PaperTiger — to score the surface. If the wall is drywall as opposed to stronger plaster, be careful not to damage its paper or wet it too much.

Cover the floor with dropcloths, as the work is messy. Using a spray bottle or a sponge and a mixture of warm water and vinegar or wallpaper solvent, wet the scored surfaces to loosen the glue. Work in strips from top to bottom, and peel off what you can do in 15 minutes or the glue will reactivate. An alternative is to rent a wallpaper steamer.

Q. We have a crawl space under the older section of our home (circa 1900). We have access to this space and would like to use it more efficiently. Our hot-water heater is down there, although we are not sure how it got down there. The floor is dirt with a vapor barrier and stone foundation; the water heater is actually in a hole that is about two feet deeper than the rest of the floor. Can I dig this out by hand without causing problems to the foundation or the rest of the house? Ideally, I would like to pour a concrete floor. How deep could or should I go?

A. If your stone foundation is not mortared in but consists of stacked, loose stones, I would not recommend it, as there is a considerable risk of collapse. Even if the stones are set in mortar, the type of mortar used in 1900 is unlikely to be sound today. And if it has been repaired, it is likely to be only a surface repair and not to be trusted to support the stones while you are excavating.

In any case, you must not excavate any closer than three feet from the existing walls and you must end up with a 45-degree slope unless you plan on building a masonry wall around the perimeter of the excavation. This must be done in alternating sections not exceeding four feet. This is a job best left to contractors experienced in this type of work; it is not worth risking the collapse of your house.

Q. The best time to do a roof replacement is before the old surface begins to leak. How can a person assess the remaining longevity in a single-ply rubber membrane (EPDM) roof? Are there any telltale signs that the end may be near?

A. If installed properly, rubber roofs have a long life. Affecting their longevity are the seams and the flashing at the perforations. The seams of a fully adhered rubber roof may begin to delaminate. You haven’t said how old your roof is, which would indicate whether the seams were glued or taped. Taped seams are longer lasting than glued seams, but, again, it depends on how well this was done. One telltale sign can be whether the roof feels spongy when walking on it because the insulation under it, put there to cushion the rubber from the rough sheathing, has become wet. So you may want to have a roofer experienced in rubber roofs take a look at it when the snow is gone.

Q. I have a question about insulating the hot-air ducts in the ceiling of my basement. Is it energy efficient to put some sort of insulation around the hot-air ductwork (particularly the long runs) in the rafters? Or is it better to just put insulation over the joists of the spaces where the hot-air ducts are? If it is advisable, what kind of insulation should I use, the fiberglass with or without the paper backing? In about three-quarters of my basement, I have a dropped ceiling.

A. If you are using the basement for recreation, sorting laundry or working on projects, the heat loss from the heat ducts helps to condition it. But if the basement is strictly for storage or sporadic uses, and its exterior walls are not insulated, there is some advantage to stapling fiberglass batts with an integral vapor retarder (to make it easier to install them and contain the fibers) below the ducts, especially the supply ducts carrying warm air (it is less important to insulate the cold-air returns). You do not need to insulate the ducts per se; it is likely to be difficult. Placing the insulation under them will help warm the first floor. If your water heater is in the basement, and it is not insulated, consider doing so.

INTERESTING TOOLS FOR DIY: Amprobe makes several tools that may help the ambitious DIYer to check the proper functioning of receptacles, whether a wire is alive or not, and to measure voltage and resistance at the service panel. Some of these tools should obviously be used with caution by an advanced DIYer with some knowledge, but the one to check voltage and other functions of receptacles should be in everyone’s toolbox. I used it in every house that I inspected to determine if receptacles had reverse polarity (a danger to polarized equipment with a fat and regular prongs) or were properly grounded. It was surprising how many were not properly wired.

Ÿ Henri de Marne was a remodeling contractor in Washington, D.C., for many years, and is now a consultant. Write to him in care of the Daily Herald, P.O. Box 280, Arlington Heights, IL 60006, or via e-mail at henridemarne@gmavt.net.

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