What causes soot along the baseboards?

Q. I hope you can help me with a problem I have with black soot above my baseboards. Our furnace has been inspected, cleaned and I have been assured the furnace is not the issue. However, I have black soot in every room above my baseboards. The baseboards are clean and they don't blow the heat anyway. This is soot because it just swirls when I try to clean it. We have painted rooms because of this but within six to nine months we start seeing it again. I've included pictures of two different baseboards.

A. This is a common problem. It may be caused by a combination of reasons: the use of many candles, smokers in the house, exterior walls that get cooler when the baseboards are not generating heat, other pollutants in the air that are drawn into the baseboards from the floor when warm air is rising from them.

If the exterior walls are only built with two-by-four studs and are insulated with 4-inch fiberglass or cellulose, they are not up to today's standards and can be cool enough in cold weather to allow light condensation on the interior finish.

This can be aggravated if the insulation was not very carefully installed and there are empty spaces around the walls' bottom plates.

Invisible condensation can form on the inside finish of the exterior walls, particularly near the bottom of the walls, which are colder. The warm air rising from the radiators, carrying any pollutants from the sources mentioned above, particularly if the floor is carpeted, deposits these pollutants on the misty walls as downdrafts descend along these walls.

If the soot, or whatever the composition of the stains is, is not thoroughly removed and the walls really cleaned, the stains will bleed through the paint over time.

If the cause of the problem is not removed, the stains will recur regardless of any cleaning efforts. Reducing or eliminating the source(s) of the pollutants and vacuuming the floors often may help, but the wall construction is harder to improve.

Q. I spilled melted wax from a votive candle in several areas on my cement porch floor, which of course, has now hardened. I tried scraping it off with a single edge razor blade only to make marks in the concrete. A pressure washer was also used to no avail. I wonder if you are familiar with some kind of solvent that might do the trick? Or do you have any other ideas?

A. Try placing a terry cloth (best) or a half dozen paper towels on the wax and put a hot iron on them. The wax should melt and be absorbed by the terry cloth or paper towels.

Have handy a bottle of mineral spirits and quickly wipe the remaining softened wax that has not been absorbed into the terry cloth or paper towels.

Finish the job by wiping off the mineral spirits with warm water and dish detergent. Repeat as needed.

Q. My house is 8 years old. In the last several years, I have noticed an accumulating black particulate on the water edge level of the toilet bowls. The underside of toilet bowl rim is stained with same black particulate. I scrub to remove from under the rim but the same black material returns as a water level stain. I have not noticed any black material in the tank at any time. Is there something wrong with the plumbing?

A. Do you use one of those toilet cleaners in the tank? If so, the black stains may be rubber particulate from the rubber flapper being eaten away by the chlorine.

It could also be caused by your water supply if the city water is treated with certain bleaching agents eating at rubber parts.

Squirrely responses: Readers responded to a recent letter about squirrels eating through vinyl siding and my asking for any help from you. I have received the following:

• "I had a problem with squirrels eating through cedar siding and plywood - solved it with a coke can painted to match siding, punched holes in can and partly filled it with mothballs. I hung the can where they had previously entered and also put some mothballs inside the siding. You need to refill the can as mothballs deteriorate with time. No squirrel problem in the past 10 years, but I still refill the can every year in the fall."

• "If hot peppers don't work, try Messinas Squirrel Stop. We had a problem with squirrels chewing the wires under the hood of our car last spring. One application of Squirrel Stop and they where gone. It's completely organic, and available at most garden centers and online."

• "I am sure you will get a lot of response in answer to your question about getting and keeping squirrels out of homes. I just wanted to let you know that we live among a grove of black walnut trees in Middlebury, Vermont, and beginning about this time of the year squirrels begin stockpiling for the winter. About three years ago we heard a lot of scurrying around in the attic but lazily assumed it was mice, which we also have but usually control with a trap placed under the kitchen stove. The next spring we discovered a trove of over 100 nuts in our attic plus a nest to boot. The squirrels had moved in! Long story short, we bought about 20 ultrasonic rodent repellers like the Victor mini pest chaser with night light and plugged them in each room of the house, including into our attic fixtures. It took about three days but the squirrels moved out and have not returned. We still have the ultrasonic repellers plugged in, though, just in case the squirrels get tempted to return. And when we had the house painted last summer, we asked the painters to close up a little hole between the roof and siding they had been using for egress."

Dried ink in a dryer: Another reader's suggestion on dealing with ink stains:

• "I had the same problem when my son left a pen in a pocket. He used (notice I say 'he') a Magic Eraser and that removed quite a bit. Yes, it's still a little blue, but not nearly as much as it was."

Was the Magic Eraser used to remove the ink stain from the dryer, and not the shirt, as was the earlier question?

• Henri de Marne, a former remodeling contractor turned columnist and consultant, is the author of "About the House with Henri de Marne" (Upper Access Publishing). He continues to take questions from readers for this column and his website, www.henridemarne.com. Email questions to aboutthehouse@gmavt.net.