Q. My wife and I own our home, a 58-year-old split-level in northern New Jersey that has hot-water baseboard heating throughout. I can't complain regarding the warmth in winter.
We are seriously considering having central air and heat units installed, as every year at this time we trudge three AC units from the garage to the windows for cooling. Unfortunately, the house has no ductwork infrastructure, and we have not gotten cost estimates in several years.
As we get older, we realize how much physical work is needed with window units vs. central air. We would like to know if it is more cost-effective to have a licensed contractor perform the installation during the peak season, or would we save money by having the work done between Labor Day and early December?
A. Since your hydronic heat is satisfactory, there seems to be no reason to dispose of it, if that's what you have in mind, to install a new warm-air heating system in combination with central air conditioning.
Extensive construction is not needed to install a duct system for air conditioning. It can be installed in the attic with ceiling registers in the upstairs rooms, which I assume are the ones in which you are putting window units.
The simplest way to get air conditioning in the upper level of your split-level home is to replace the window units in those rooms with ductless wall units. Mitsubishi, with which I have had some experience, manufactures such units, and they are quiet and efficient. Other brands are Sanyo, LG, Fujitsu and Carrier. The advantage of these wall units is that you won't have problems with cold air and condensation in the attic ducts in the winter.
Look in your Yellow Pages for contractors who install such units. Get two or three estimates and weigh the suggestions. Having the work done in the fall, after the air-conditioning season is over, is likely to cost less.
You may find that installing three units is quite a lot more expensive than two because the outside compressor will need to be larger to accommodate the third one. Perhaps there is a way to have only two.
Q. Some type of mold has been developing on my roof in the last few years. The shingles are a dark gray, and the mold is only on the northeast side. The roof was installed in 2005. Is there a way to get rid of the mold?
A. The photo you sent illustrates the development of algae, which forms where roofs get the least amount of sun. There are several ways to get rid of algae and to prevent it from recurring.
On a windless day, you can spray a solution of equal parts fresh Clorox bleach and water onto the roof from a ladder using a garden sprayer. Do not overspray; a gallon of the solution should cover 50 square feet of roof.
To prevent damage to metal gutters and downspouts, keep a gentle flow of water running through them while there is runoff from the roof. Wear rubber gloves and eye and skin protection. Soak all vegetation below the roof with water and cover it with plastic before spraying, then rinse the plastic and soak the vegetation again when you are done.
Or you can spray the roof with Spray & Forget (www.sprayandforget.com) or Wet & Forget (www.wetandforget.com). Both claim to be environmentally safe, and readers have reported good luck with both. As with all products and methods of dealing with moss, lichen or algae, you must follow directions on the containers and allow plenty of time -- sometimes months -- before seeing results, depending on the extent of the infestation.
You also may want to consider installing zinc strips just below the cap shingles. Over time, the zinc leaches ions that poison the spores responsible for the growth of algae, moss and lichen. You can buy zinc strips in box stores and some hardware stores, or you can buy them at www.stainhandler.com.
Q. We live in a townhouse, with our washer and dryer on the second floor. The dryer vents into the attic and not outside. As seniors, cleaning out the vent is a hassle because we can't climb into the attic or move out the stacked washer/dryer to get to the vent.
We are wondering if there is any other way to vent the dryer, which is gas. Our association will not permit any outside venting. I did see a water-filled unit that is attached to the wall above the dryer to accept the vent hose. However, it said not to use it with a gas dryer.
This situation has us concerned about fire safety. I have had to hire a handyman to clean out the vents a couple of times, which is costly. If you have any suggestions, they would be greatly appreciated.
A. Venting dryers and bathroom and kitchen fans into an attic is a very poor practice. It introduces moisture, heat and grease in a space that is not designed to receive them. Lint and grease are fire hazards, moisture promotes molds, and heat will cause snowmelt that often results in ice dams.
In your case, the builder did not seem to have much choice. The culprit is your association, which is showing its ignorance of the risks it is creating with this blind policy. The results may come back to haunt the association when damages eventually require repairs. Members could bring lawsuits against the officers.
The only answer I can think of is to take up the matter with the association and show them my answer to emphasize your point. Best of luck.
Q. We just took off the wood paneling in the basement to prepare the room for the new, updated refinishing. We realize now that when this was done about 20 years ago, the carpenter did not use any insulation or vapor barriers. Twenty years ago, we did not know any better what to look for! We have three contractors lined up for this job, and this time we want to ask the right questions.
We still want to use good paneling; I like the smell of a great wood. What treatment goes under the paneling, and in what order? We have no problem with water because a French drain was done with a sump pump before the paneling in the basement. The walls are cinder block and never caused any problem. Half of the basement stayed unfinished -- also no problem. I need only a dehumidifier in the summer to keep it sweet.
A. Unless you know that the soil against the foundation is a coarse material such as sand or gravel, that there is a properly functioning foundation drain and that the grade slopes gently from the foundation to move away water, insulating a foundation -- especially one made of blocks -- from top to bottom may be risky. Insulating the entire wall allows frost to penetrate deeper, which can push in the walls.
When in doubt, it is best to insulate only from the top to 3 feet below grade, which allows some heat to flow out and keep the frost at bay. This can be done with 1-inch-thick rigid extruded polystyrene (XPS) or polyiso. With these materials, there is no need for a vapor retarder. If you are sure that all is well and there is no risk, go ahead and insulate to the floor with the same material.
Since you had paneling, you must have some studding in place. If there is at least a 1-inch space between the framing and the foundation wall, slip the insulation behind the framing. Otherwise, cut it to fit between the studs.
If the framing has been removed, insulate and then reframe.
Q. We are having a problem with our insulated steel front entrance door. It is sagging. There is a greater gap between the door and the wood frame at the top than at the bottom that is causing the door to drag on the threshold. Is there a way to fix it so it does not drag anymore?
A. It sounds as if the screws in the top hinge have loosened. Try tightening them or, if need be, replace them with longer screws. The middle hinge also may need to be tightened.
Q. How can I increase the air intake in my attic? I have a ridge vent and two gable vents, and no overhangs. The attic gets very hot from being in the sun all day. Should I install other vents at the bottom of the roof to increase ventilation? A fan?
A. A ridge vent in combination with gable vents is not very effective at removing heat from an attic. You should install some soffit venting system and seal the gable vents, which cause air to flow only from the gable vents to the parts of the ridge vent closest to them, doing little for the rest of the attic. The gable vents can be closed from inside with pieces of plywood painted matte black.
The easiest way to provide low roof venting where a roof has no overhang, and therefore no soffit in which to install venting, is to use DCI Products' mid-roof intake SmartVent (www.dciproducts.com). It can be installed under the roof shingle course above the wall plate insulation, thus acting as a soffit vent. A 1-inch slot will need to be cut in the roof sheathing as an intake for air.
Q. My attic has two layers of fiberglass insulation between the floor joists. I estimate that each layer is 3 to 4 inches thick. The contractor who did a blower door test told me that this insulation is not doing anything and is worthless. He is proposing to spray foam insulation between the rafters and to make my attic unvented. He wants to close the soffit and ridge vents.
Do you agree with closing these vents? He told me that by creating an unvented attic, its temperature would not get much hotter than the living space in the summer and not much cooler in the winter.
A. Anyone who is telling you that 6 to 8 inches of fiberglass is worthless needs to be able to tell you why he or she is making such a statement. Unless he/she has credible reasons for saying something so drastic, I would suspect them of ulterior motives, such as wanting to sell you an expensive foam spray between the rafters.
If you want to increase the R-factor of the attic's insulation, and you have room to do so, it is far less expensive to blow several inches of cellulose over the existing fiberglass.
If your attic is floored and used for storage, this is more involved, and it may be worth considering several options. Spraying closed-cell foam between the rafters is one of them if you are really concerned about making your house more energy-efficient. But this expensive solution depends also on the rest of the house.
If you have a two-story house with standard two-by-four construction and windows, spending a large sum to make the attic more energy-efficient is putting your money in the wrong place. Instead, look at replacing the windows and reducing air infiltration, which the blower test should have identified.
I need more information about your house to be able to guide you in the right direction.
• 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 email@example.com. His book, "About the House," is available at www.upperaccess.com and in bookstores.
© 2012, United Feature Syndicate Inc.