Don't trust a door-to-door contractor
Q. Is putting a 2-inch layer of macadam over existing macadam a good idea? I had my driveway (100 by 15 feet) done about 10 to 12 years ago, and it is cracking in the same places as before and looks like it needs to be replaced.
The contractor that did the job dug up the front 75 feet then put down stone and blacktop. He said that the back 25 feet was good and put down stone over that and topped it off with a layer of blacktop. I waited the recommended time before I sealed it. Every three years, I had it spray coated by a reputable contractor. I kept sealing the cracks with crack sealer.
Now it is cracking and peeling. I know I get water drainage underneath the driveway from the property next door, and at times I get water in the basement on that side. In the winter, it freezes, and the driveway picks up. I am trying to control the buildup of water on that property by sloping the ground to a runoff on my property through a 4-inch plastic pipe leading to the street.
A contractor who knocked on my door suggested the overlay of a 2-inch topping and told me he would pitch all drainage to the front of my property. Do you have any suggestions?
A. My first recommendation is to never deal with contractors who knock on your door with all kinds of promises. You are very likely to get a poor job and never see them again. You should get the advice of a long-standing contractor whom you contact yourself to save yourself a potential headache. This is the same advice you'll get from consumer-protection organizations.
Poor water drainage is a major contributor to the driveway problem. Getting rid of the water with a drain system is a very good approach. Putting 2 inches of new asphalt over the existing driveway would probably be the least expensive option and would relieve the symptoms for a while. Eventually, the driveway will crack again - most likely in the same places it does now. When it does crack again, hire a reputable contractor to seal the cracks with a hot, rubberized sealant, which will still need to be done periodically. You are right in not seal-coating any new pavement for two to three years in order to give it plenty of time to cure.
Q. My poured-concrete driveway is about 3 years old and is beginning to develop too many chips and smaller pot holes. I do not use salt to melt the winter's ice. I would expect a few small holes over time, but at the rate it is going, I am afraid that this will continue until I have no driveway left. Can or should I patch the holes and/or seal the driveway? If yes, how can I best match the color so it doesn't look like my driveway has a case of pox?
A. It sounds as if your driveway is scaling. Scaling can occur if the concrete was not air-entrained or if too little entrained air was used. It can also be caused by the finishing operation performed while bleed water was still on the surface. As bleed water is worked back into the top ˆ¼ inch of the slab, the result is a very high water-cement ratio and a low-strength top surface. It can also be due to insufficient or complete lack of curing, which results in a weak surface that is very vulnerable to the freeze/thaw cycle when there is moisture on the slab from weather or cars.
Salt on cars is also a cause of scaling. You should remove all loose particles with a strong jet from your garden hose or pressure washer, followed by a vinyl-reinforced concrete-repair material. You will probably not be able to match the color, but time helps. Wait a year or so before applying sealant.
If the surface to be repaired is too much for a do-it-yourself job, have a concrete or masonry contractor perform the repairs. Calcium and sodium chloride de-icing salts should not be used, and it is a good idea to seal exterior concrete (as opposed to concrete in a garage or basement) by spraying or brushing it with a 50-50 mixture of boiled linseed oil and mineral spirits. Buy boiled linseed oil at paint and hardware stores. There are other sealants available commercially in masonry supply houses.
Q. I'm contemplating changing our forced-hot-air furnace over to gas. Our current oil-fired unit is over 40 years old and needs to be replaced. I imagine we'd also switch our electric clothes dryer over to gas. Can you direct me to a neutral source that discusses the pros and cons of each fuel? I'd also be interested in your opinion. In addition, I'd like to know of any rebates offered for gas-service startup and appliance purchase. We live in Shrewsbury, N.J., so our gas utility is natural gas. I'd also like your opinion on installing central air conditioning with the furnace/air handler. We live in a post-World War II Cape Cod with a family room (14 by 18 feet) added to the rear. I know most of the neighbors have a hard time cooling the second floor in these Capes, but I'd sure like to get rid of the window air-conditioning units.
A. Your decision depends on the cost of each fuel in your area. You should be able to get an estimate of your annual cost from the gas company, as they review the amount of oil you use. If the figures are comparable, gas may be the better choice in the long run, as gas furnaces are cleaner and more efficient than oil-fired furnaces. Gas-fired furnaces still should get yearly safety checks. Your local utilities can tell you what rebates, if any, are available. Having central air-conditioning installed at the same time you replace the furnace is a good idea, and an experienced heating, ventilating and air-conditioning contractor should be able to balance the system so the second floor is comfortable. This may require adding a considerable amount of insulation on the attic floor if you do not already have at least R-36. This is the simplest way to reduce the heat load to any rooms below an attic.
Q. In a recent column you wrote about the use of Shingle Shield. I have mold or dark-green mold growth on my roof shingles and would like to know how to treat this problem. Would the use of the zinc plates prevent recurrence of this mold-type growth?
A. Shingle Shield Zinc Strips are effective in preventing the growth of algae, moss and lichen on several types of roofs, asphalt, fiberglass, wood, tiles, etc. They do not remove existing growth very well; that may take a very long time. However, you can remove existing growth by spraying the roof with Roof Deck Cleaner. You can buy Shingle Shield from several sources on the Internet. ZincShield is another choice, (800) 440-3010; they also sell LiquidZinc for treatment of existing growth. Once the roof is cleaned of these growths, any zinc strips applied by following the instructions should prevent further growth.
Q. I have a lot of leftover Drylok for masonry that seals and prevents water leakage. I used it in my basement to treat the cinder blocks, and it worked well. I would like to know if it is OK to try on my 25-year-old wooden garage door. I'm getting some water damage where the panels come together when you close the garage door. I wanted to treat the seams only with this product, but it says it's for masonry, not wood.
A. The answer is on the can: "For masonry only." You can purchase a wood preservative for the seams of your garage door, or you can apply whatever paint or stain is already on the door.
Q. I read something that might be the answer to a question that I have had for quite a few years about my garage, which has a severely cracked and heaving concrete floor. One wall and part of another wall are out of line, because the ground on those sides has settled by a foot. The ground next to the back end of the garage seems to be on firmer ground, but I see a wash of gravel next to a vertical crack in the foundation.
You suggested to a reader in an article to hire a certified home inspector, which is something that never occurred to me. Several years back, I contacted a few mud-jack companies for an estimate on mud-jacking the floor. I got estimates ranging from $4,000 to $8,000, but these companies would not guarantee that mud-jacking would solve the problem. One person even suggested tearing down the garage was the best thing to do. Before I considered spending this kind of money, I would have to be assured that the same thing would not happen again.
We have lived in this house for 30 years and did not notice the cracking and sinking until maybe 15 years ago. I have asked different people, including the mud-jack people, our village home inspectors, etc. No one had any suggestions. I mentioned my concerns about the garage floor again to one of my sons, and he said that a long time ago an old neighbor said that a creek runs along side the area of the garage where the soil has sunk so much. I wish that was mentioned to me at the time. This might be the case, as our house and driveway are a good 8 feet higher than the next lot, and there is a storm drain near our elevated driveway that goes out to a lake about two miles north of our house. It seems to me that maybe this garage should never have been built where it is standing. Any suggestions you have would be appreciated also.
A. In your case, I would advise you contact a soils engineer. It does sound as if you have an underground spring that has eroded the bearing soil under the affected garage walls and floor. The wash of gravel you see is a good indication. If you want to save the garage, once the sinking of the soil has been solved and, hopefully, corrected for good, the parts of the garage walls that have settled can be lifted back into place and the foundation can be stabilized by firms that use special screws that are driven into solid ground. One such specialist is Grip-Tite, (888) 365 9552, www.griptitefoundationsystems.com. They can also level your floor or a new floor, can be poured over the sunken one, unless you can find a mud-jack firm willing to raise it and guarantee the work.
Henri de Marne's column appears Sunday. He was a remodeling contractor in Washington, D.C., for many years, and is now a consultant. His book "About the House" is available in bookstores and at www.upperaccess.com. 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.
ˆÂ© 2008, United Feature Syndicate, Inc.