Boiling water removes adhesive from concrete
Q. My condo has a concrete balcony that needs some repair. An outdoor carpet has been removed at the request of our association, who said it should not be covered. I would like to paint and seal it, but it needs to be cleaned (old glue buildup removed) and smoothed out. How should I go about doing this, and what type of paint and sealer should I use? I would appreciate your help.
Palatine, Ill.
A. To remove the adhesive, you need to pour boiling water on a small area at a time (2 feet square). Wear heavy rubber gloves and be careful not to scald yourself. Once you have poured the water on, scrape the softened adhesive with a broad-blade putty knife. You may need to repeat the treatment to remove all traces of the adhesive. Failure to do so will give you paint-adhesion problems. Once you are sure that all the adhesive has been removed, paint the concrete with a concrete deck paint following directions on the can.
Q. We live in a house in Short Hills, N.J., with a serious moss problem on our roof. The roof, we have been told, is a 40-year roof (good quality) that was installed 15 years ago by the previous owner. We noticed about five years ago that the roof started to appear stained on the eastern side of the house. Then, in the last couple years, moss and lichen started to appear on the east side, both over the main roof and the roof over the sun porch. It is quite prevalent.
Some of the moss patches are as large as 3 inches in diameter, and there are hundreds of them. The lichen patches are smaller and flush with the roof, but there are several hundred of these, also. Part of the roof is in partial shade, but some moss-infested areas are in direct sunlight, including the stained areas. We have a lot of large trees surrounding the house, but neither the shade nor the dripping appear to be related to the moss. We would appreciate any advice you can give us.
Via e-mail
A. Moss and lichen need moisture to grow. It may be that the 15-year-old shingles are not drying fast enough, even on the sunny side of the roof. As shingles age, they absorb moisture and retain it longer. They can also be affected by excessive moisture from the attic. Even though these growths are unsightly, they do not materially affect the life of asphalt or fiberglass shingles. But they do shorten the life of cedar shingles and shakes.
To kill the growths, try spraying them with a mixture of three parts white vinegar to one part water on a calm day. It will take a long time for the moss and lichen to die off and eventually be removed from the roof by heavy rains and snow. If your roof is made of cedar shingles or shakes, you can also have it pressure-washed by a commercial service; it's too risky for the average person to do it.
Be sure that the service you choose is insured against all perils, including injuries to their workers. You should not pressure-wash asphalt or fiberglass shingles, as it will remove their protective mineral granules and hasten sun damage. If the staining of the roof is somewhat blackish, it is probably algae growth. This usually occurs on shady sides, but it can also occur under the circumstances mentioned above.
To get rid of it, spray the roof on a quiet day with a solution of three parts fresh Clorox bleach to one part water. It will take several weeks for the algae to die. If you decide to do the job yourself, work from a ladder, use a garden sprayer and apply the solution at the rate of 1 gallon per 50 square feet of roof. Do not overspray; there should be no runoff, and do not rinse the roof after treatment.
Prior to spraying, protect all vegetation below the roof by soaking it and covering it with plastic. Rinse the plastic and soak the plantings again afterward. If you have gutters, you should have someone run water through them while the solution is applied in order to dilute any drippings. Wear heavy rubber gloves as well as eye and skin protection.
Q. We bought our house in 1999. A couple of years later we noticed powdery wood on some spots on the basement floor. We called our pest-control company, who identified it as pine wood borer. (They said it could have come from the wood lying around the construction sites.) They treated it with some kind of boric acid solution, but warned us that there may be more, which is difficult to tell, as they could be inside the wood, and we could notice their presence only when they come out. Anyway, the problem is still there in other spots. We want to treat it ourselves. What action should we take?
Via e-mail
A. The application of an insecticide to the infested areas by the homeowner is often sufficient. But finding the appropriate pesticides is not so easy because there are so many pesticide restrictions now. Go to a hardware or garden-supply store and see what they have for these borers (sorry, not too helpful).
Regarding the use of borates, you should be able to get Solubor, a fertilizer-grade borate that's available from agricultural-supply centers. Another choice is Penetreat from I Wood Care. Their toll-free number is (800) 721-7715. It comes in a powder form that is mixed with water. A 3½-gallon pail will make 14 to 15 gallons of solution and treat 2000 square feet of surface. It costs $77.75 plus UPS shipping. A 6-gallon pail ($127.45) is also available. It can be brushed on or applied with a garden sprayer to all surfaces. If you have access to the Internet, their Web site is www.iwoodc.com.
A much less expensive way to go is to make your own solution by mixing 1.2 parts borax (1.2 pounds Twenty Mule Team Borax) to 1 part (1 pound) boric acid in 1 gallon warm water as follows: Mix the borax first, until it is dissolved, then add the boric acid and mix until it is dissolved. Finally, add another gallon of water, as the original mixture is too concentrated to spray or brush. Apply with a garden sprayer.
Q. I've just moved into an apartment with a brand new stainless steel sink. Much to my dismay, what looks like mineral residue from water has left "rings" in the brand new sink. I scrubbed them with a baking soda paste, which had no effect. What would you recommend? I heard that a cleanser named Bar Keepers Friend may be effective. I can't get rid of these water stains. Help!
Via e-mail
A. You should try Bar Keepers Friend, it's a great cleaner. Another choice is Milsek's Stainless Steel Cleaner. Their Web site is www.milsek.com, (800) 216-9517. According to the manufacturer, their Stainless Steel Cleaner "Removes finger prints and watermarks, quickly, while leaving a fresh coconut scent and a wonderful shine." In light of my own experience, and that of many of my readers with Milsek Furniture Polish & Multi-Purpose Cleaners, their stainless steel cleaner is bound to be great.
Q. I read your column every week. It is most valuable. What is your opinion of sealcoating an 18-month-old driveway? Is sealcoating necessary or helpful? The people that do sealcoating, of course, say it extends the life of the driveway. The contractors that do the paving (asphalt) say that sealcoating is not necessary. What is your opinion?
Via e-mail
A. Sealcoating is very much worthwhile. It's best to wait two years before considering applying a sealer. It usually takes that long for the oils in the asphalt to evaporate and for the asphalt to harden. If your driveway is in the shade, you probably need to wait even longer than two years until the asphalt turns gray. As asphalt ages and its oils dry up, it absorbs water and can begin to deteriorate. It is also susceptible to damage from the oils that leak from vehicles.
There are basically two kinds of sealers: shiny and dull. Sealers that dry shiny are asphalt-based, such as Gilsonite -- a cutback asphalt with a solvent. The best sealers have a matte finish and are coal tar-based, but we are running into a national problem. Coal tar is derived from coal-burning and is heavily used in the production of aluminum, which is at an all-time high because of the high quantity we export to China. So we are faced with a huge shortage of coal tar, which may no longer be available.
A new type of asphalt-based emulsion has been developed that has a matte finish and resembles coal-tar emulsion. It's fine to use. Either coal-tar emulsion or asphalt-base emulsion can be slippery if there is no sand in the mix. Be sure that the mix you buy contains a sand filler. Monsey and other rubberized products are very good. All sealers must be applied in thin coats, or they will develop craze cracks, referred to as "alligatoring." Two thin coats are far better than one thicker coat for that reason. Once alligator cracks form, the sealer is no longer waterproof, as water gets into the cracks.
Q. I recently read your column on an odor product "Knock Out" that works, but I can't seem to Google "knockout" and get their Web page or a place to buy the product. Can you help?
Via e-mail
A. You can order Knock Out on their Web site www.ptbent.com or by calling their toll-free number (866) 478-2368
© 2007, United Feature Syndicate, Inc.