Many products clean pine sap from bricks

Q. I enjoy your column in our local paper. Here's the problem I need help with: We have a large pine tree in our backyard. It hangs over our brick patio, and subsequently sap from the pine cones drips onto the patio.

I've tried hand sanitizer and denatured alcohol on the sap. The patio looked good until it dried, and was then simply "smeared" with white spots. We would appreciate a product recommendation. Many thanks.

A. I am surprised that alcohol and hand sanitizer did not work, as both are recommended for removing pine sap.

First, try Lestoil; several readers have used it with success. Others have used Goo Gone, but first make sure the bricks on your patio have been sealed and that the sealer is still effective by spraying some water on the bricks and watching for the water to bead.

Spray Goo Gone on the sap, wait a couple of minutes, and scrape the sap off. Repeat if needed. Then wash the bricks with soap and water. OOPS has also been tried with some success. Be sure to read the instructions before applying it.

Other successful methods I've heard of are spraying Oxy-Boost (from ecogeeks.com), letting it soak in for five to 10 minutes, and then pressure washing. Other products include Mean Green, a concrete degreaser, various citrus-based cleaners, or a construction solvent cleaner.

Hopefully, one of those will work for you.

Q. Thank you for responding to my earlier question, and asking me to provide the additional information you needed to try to figure out the puzzling problem I have with my 4-year-old garage.

My original question was: "We began seeing what we initially thought was a rain leak showing up on the floor. However we could not find anywhere that water might be coming in through the siding or the roof. It occurs in the same spot about 4 feet from the south and west walls, and is about 1 by 4 feet in size. It is 'damp' most of the time and occasionally will make a large puddle.

"The builder concedes that condensation is probably the answer."

Here are the answers to your questions: 1. This occurs during winter and summer. 2. The floor is 6 inches above grade but the yard is quite flat. 3. I rather doubt that plastic was used; the concrete was poured over the usual 4 inches of normal gravel "base." I would have to contact the builder again to be sure.

A. Yours is definitely an unusual problem, and after considerable research, I haven't found any reliable answer to it. So I'll mention what I think may have been causing the recurring, mysterious wet spot based on experience, which may or may not be very helpful.

I doubt that condensation is the cause of the recurring wet spot, as it could only occur in late winter or early spring when warm, moist air comes in contact with the slab, which is cold after a winter's cooling of the earth beneath it. I have also seen it happen, but very rarely, in the fall if very hot and extremely humid air suddenly descends on the area. And condensation would occur throughout the entire slab, not just in the same relatively small spot.

Even though you haven't answered my question "Did the builder find a wet spot on that area of the ground as they prepared for the pour?" I'll venture a couple of guesses as to what is creating your problem.

Let's assume there is a wet spot in the soil (or a tendency for it to be a wet area, although dry at the time of the pour) because of the soil's composition or a rotten tree stump, long gone, etc.

If no vapor retarder was used over the crushed stone, and the stone base laid in that spot contained a lot of fines (fine particles of stone often found in the delivery), there may be capillary attraction through the slab when the soil becomes wet from rain, watering the lawn or other plantings nearby, since your yard is flat.

On the other hand, if a plastic vapor retarder was installed and the builder used the rather common practice of placing a layer of sand over the plastic to speed the finishing process of the concrete, it can take years for the layer of sand to dry through the concrete, since it can't drain through the plastic. But this would also most likely happen throughout the slab. This practice was recommended by the industry in the early 2000s until it was found to cause serious problems, and it has now been withdrawn.

If one of these hypotheses is correct, there is not much that can be done to remedy this problem, short of tearing the concrete up.

Since you mentioned in your earlier question that it is not a serious problem, it does not seem to be something to be concerned about.

Q. I hope you can help me. I live in Vermont, and my condo is on the ground level. Each year, in the kitchen next to the radiator, I find dead ants on the floor, many when we return from Florida, all in a little pile and then fewer as time goes on. This has been happening for about three years now. I'm stumped, and no one else has ever heard of this. Any ideas?

A. Since the dead ants are found only in one location, I suspect they are carpenter ants, and they may have a nest in that location. Or perhaps it is the only way they find access inside, which would be quite unusual.

It is possible that your condo association is having a regular spring application of a carpenter ant spray or granular control. Check with one of the condo association officers.

Q. In my bathroom I have a vanity with two sinks. I use the closest one (on the left) most often and the other one (on the right) only occasionally. Earlier this year I began to notice a sewer smell coming from the left drain when the water was turned on, even though it gets used every day. I tried running water in one before using the other. I also tried running water in both at the same time. I've used up all of my ideas and have none left, so I thought I would ask if you have some thoughts on that subject.

A. The following answer is partially excerpted, with some additional information, from my book: "About the House with Henri de Marne" on page 178 of the printed edition in the chapter on "Plumbing, Electricity, HVAC." It is found on page 276 of the e-book edition under the same title.

What are your bowls made of - vitreous china or a plastic material, such as cultured marble? Plastic sinks can outgas chemicals used in their fabrication for quite a while, but since you have noticed this odor only recently, the culprit may be bacteria in the overflow tube. Since this occurs in the sink you use most of the time, this could be your problem.

First try spraying full-strength bleach copiously into the overflow hole. If that does not cure the problem, try spraying Nok-Out into the overflow tube. You can buy Nok-Out at www.nokout.com.

If that does not do the trick, remove the pop-up stopper, seal the end of the overflow by stuffing a rag tightly down the drain a few inches (be careful to have enough of the rag sticking out to be able to remove it), and pour bleach down the overflow.

If the pop-up stopper is captive (tied to the control rod that operates the stopper), you can free it by unscrewing the knurled nut that ties the control rod to the waste pipe under the sink and pulling it out enough to free the stopper. You will see that the stopper has an offset ring on the bottom. Put the control rod back and hand-tighten the knurled nut. When you are done, put the stopper back, turning it until the offset ring is clear of the control rod.

Great information from a Vermont boat restorer: "I am writing in response to the homeowner battling mildew on her bathroom tile caulking, which you surmise is silicone.

"My outfit restores old wood boats, almost all of which have deck seams caulked by some variant of Sikaflex, which is available from Jamestown Distributors and virtually all marine supply companies. (Sikaflex is not a silicone-based product, but when cured, it exhibits similar elastic and stain resisting properties.)

"We always dread the day that comes with every project when the seams must be cleaned without marring their edges.
"We've tried everything, until I discovered the Teakdecking Systems (TDS) reefing hook. The TDS reefing hook is available from Jamestown at jamestowndistributors.com.

"The reefing hook is a gift from heaven. The directions that came with the tool suggested scoring the edges of each seam with a razor blade - I would use a utility knife and new blade, but doing so risks slicing the sides of the seams, so we did not do it.

"Since that risk does not exist with tile, slicing along the edges, followed by the reefing hook might clean the seams more effectively."

A. Thank you for introducing me to this useful and inexpensive tool.

• Henri de Marne was a remodeling contractor in Washington, D.C., for many years, and is now a consultant. His book, "About the House," is available at www.upperaccess.com. His website is www.henridemarne.com. Email questions to henridemarne@gmavt.net, or mail First Aid for the Ailing House, Universal Uclick, 1130 Walnut St., Kansas City, MO 64106.

© 2016, United Feature Syndicate Inc.