Bug expert may be able to explain mysterious stains

Q. All of the sudden this past summer, on two occasions, the wood siding on our front entryway was covered with black/brown spots from some type of bug. They also appeared under both exterior lights. I literally had to scrub each board with soap and water and a hard scrub brush to clean it off. It was a lot of work, and now, they blasted my siding again! It occurred overnight on both occasions.

This has never occurred in years past. Can you offer some solution that will prevent this mess from happening again? Maybe something applied onto the stained cedar?

A. Did you have the lights on all night? They would attract insects and their predators.

I am assuming that the front entryway has a concrete or wood stoop or covered porch, and since you were able to remove the spots, it is not artillery fungus. Not only would artillery fungus be nearly impossible to remove, but it occurs only in the moderate temperatures of spring and fall and would be found above organic mulch. It is caused by the organic mulch’s disintegration.

If you live near a body of water, the spots may be the fecal deposits from mayflies, which swarm in huge quantities at certain times during the summer and are attracted to lights.

I suggest you consult an experienced pest control professional or an entomologist in the extension service at your local university.

Q. I hired a painting contractor who I have used several times before to power-wash my two-story, vinyl-sided house. When he was finished, there was a white film and streaks on the windows that we initially assumed was soap. However, when we went to wash it off (within two days), it could not be removed. We tried ammonia, paint thinner and CLR to no avail. The contractor initially would not return any of my calls, but eventually said he used a product with TSP in it and that it would scrape off. We have tried scraping, but without substantial improvement. Any suggestions on how this can be removed and we can save these windows?

A. The film should have been washed off right away before it dried. Here is a suggestion akin to the old saying “the hair of the dog that bit me” — using the culprit to soften the dried residue: Try mixing a solution of TSP (if it is available in your state) or TSP-PF at a ratio of 1 cup TSP to 3 quarts water; wash one window using a soft pad and rinse immediately. If it works, do the other windows. If this is not successful, it may be that the TSP, and/or whatever else the painting contractor used, has etched the glass, although it is unlikely.

Q. I have tried using Lime-Away, as you suggested, to clean my glass shower door, which looks like it has soap scum on the bottom part of the glass. I had tried to clean it with Scrubbing Bubbles, Tilex Mold & Mildew remover, CLR and vinegar without success. Any other suggestions?

A. A woman who read your question and my answer was kind enough to send the following:

“A reader asked for the best cleaner to clean soap scum after trying multiple products. I thought I had ruined the finish on my fiberglass shower and had tried everything to clean it. I had a mark on the flooring that looked dirty despite being cleaned. A friend told me to use Mr. Clean Magic Eraser. I was skeptical that anything would work, but proceeded to use it. My husband and I were amazed! It looks like new. I then proceeded to use it on the soap scum on the shower doors and was just as pleased. They make a Magic Eraser for bath and shower. Please pass this on to your reader.”

Thank you for this great solution, and it is done!

Q. What are some of the best VOC-free flooring options for a concrete basement floor? We run a dehumidifier in the non-winter months to control the musty smell and have never had water down there — we now want to finish it into usable office space. You have mentioned XPS with plywood over it in a previous column. Is this a VOC-free combination? What exactly is XPS?

A. The acronym XPS stands for extruded polystyrene, a hydrocarbon insulation that is almost impervious to moisture transmission; it is not supposed to outgas. Dow Chemical manufactures Styrofoam XPS, also known in the trades as Blue Board. Pink Foamular is another very commonly found XPS.

If you want to add insulation to the concrete floor, this is a good solution, but vinyl tile also is an option.

Q. You’ve helped us in the past with noisy oak floors, so I thought I’d run another “stumper” by you and hope for a reply. We just bought a house, built in 1956. It has many problems, stemming mostly from geriatric neglect. One problem surprised us. As we repainted every room in this one-story raised ranch, we discovered heavy dampness in two bedroom closets. In both, the rear walls show patches of moisture; one near the ceiling, the other near the floor. The wetness can be felt, but the plaster seems sound.

We suspect inadequate ventilation in the attic, which is full of rolled insulation. There is no roof ridge vent. The dampness seems to follow high-humidity weather patterns. I cleaned both of the two end-wall vents under the roof peak, but the impact was only minimal.

We’re waiting to have a roofer install a ridge vent, but I wonder if this will fix the problem and why the moisture affects only the two spots in two closets. We’re afraid to move anything into these areas until we’re sure we have a solution. Have you seen anything like this? Do you have other suggestions that we might try?

A. At which time of year did you discover the dampness in the two closets? If in the summer, the dampness may be caused by the lack of ventilation in the closets during the high-humidity times you have identified. If in the winter, the dampness may be due to condensation on areas of the walls in which there is an insulation deficiency, particularly if the affected walls are exterior.

Solving this may require adding rigid insulation to the closets’ exterior walls and covering it with new drywall.

A new ridge vent, an exhaust port, would not help unless there is an equal or greater amount of intake ventilation provided by soffit vents. I don’t think this is what is causing your problem.

Q. We have a skylight in our bathroom that appears to be 3 square feet. The back of our house faces west, and the afternoon sun coming in through the skylight is incredibly hot during sunny summer days. We’ve investigated blinds but we are not big fans of the look. I heard about something you can put over the outside to dim the light and the heat — but not all the way. Are you familiar with this or do you have any other recommendations?

A. Shade companies can install a film on the inside surface of the skylight glass, which blocks most of the heat from the direct sun while only slightly darkening the room. We have a similar situation and had a 3M Scotch film put on with great success.

Q. Recently, my father had work done to resurface a parking area with a new coat of asphalt. The individuals who performed the work failed to provide a level surface in some critical areas where vehicles are parked. How might you suggest my father address these depressed areas, as there is a collection of water and dust that will impede future efforts to reseal the surface? The individual who was hired has refused to address this matter.

A. The best way would be to have the contractor who resurfaced the parking area, or any other asphalt contractor, add some asphalt in the low spots and roll it to compact it, but that is unlikely to look very good.

It is not unusual to have low spots in asphalt or concrete paving as it is very difficult to achieve perfect drainage. It should not be that hard to clean the low spots of any dirt accumulation in the summer when the asphalt is dry just prior to applying a sealer.

I hope your father knows that asphalt should not be sealed until all the oils in the mix have evaporated, which may take two to three years. Sealing asphalt before it is thoroughly dry will keep it soft and subject to damage from vehicular traffic, especially in areas where cars are parked.

Q. My mom gave me a cedar chest that’s around 74 years old. The inside is beautiful — looks new. She covered the outside with contact paper, which I removed. There is a sticky residue left on the wood. What product will remove this and what else should I do to restore the outside, if possible?

A. To remove the adhesive from the outside of the chest, try the following until you find the right method: Apply heat with a hair dryer or heat gun, increasing the temperature slowly so as not to damage the wood, and scrape the loosened adhesive. Spray WD-40 on a small area and let it penetrate for several hours. Other products you may use include cooking spray, Goo Gone or lighter fluid. In all cases, scrape the residue with a plastic scraper in order not to damage the wood.

After removing all adhesive residue, clean the chest and polish it at the same time with Milsek Furniture Polish, available in Ace Hardware, True Value Hardware and Do-It-Best Hardware stores and other retailers. Or you can order it online at www.milsek.com.

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 email at henridemarne@gmavt.net.

© 2013, United Feature Syndicate Inc.