Cold house keeps residents chilly

Q. Just recently, there was an article detailing signs of insufficient attic insulation. The particular signs mentioned were no snow on the roof and icicles dangling from the gutters. I did a neighborhood drive by, and my house hasn't a speck of snow and many others do.

My family has said that our second floor is freezing, and I'm inclined to think that the culprit is the original insulation circa 1970. We've made many improvements over the years but never in the insulation. I'm guessing that we are overdue, and, before my family moves out for warmer environments, I wanted to contact you for your recommendations on how to improve attic insulation.

We have a 40-year-old center hall colonial with the front facing the east and the back the west. The attic is accessed by a pull-down staircase and is unfinished. We just had a new roof and gutters put on during the summer of 2008. A previous improvement in 2002 had us adding another heat and air zone. This newer furnace is in the attic. As I look back, even with this modernization to an upstairs zone of heating and air-conditioning, certain rooms on the second floor just never feel comfortable.

A. The likely reason why you have no snow on the roof is the new furnace in the attic. Having no snow on the roof when others do is only a problem if the melting snow ends up as ice dams that cause leakage in the house; gutters and downspouts filled with ice, damaging them, and huge icicles hanging from the eaves and the gutters. If none of these are present, I would not worry about it.

However, if you are suffering from any of these ailments, and since it is unlikely that the new furnace can be relocated, the most effective, albeit expensive solution, is to have closed-cell polyurethane insulation sprayed onto the roof sheathing, rafters and gable walls to a depth that will prevent most of the heat generated by the furnace from being lost through the roof and walls.

The attic will become a conditioned space - warmer in winter, thus helping the rooms below by conserving the furnace's standby losses, and cooler in summer, thus reducing the load on the air-conditioning. It will also reduce your energy consumption, summer and winter, by protecting the furnace and air-conditioner from wide temperature fluctuations.

If you have gable vents, they should be closed, as there will no longer be need for ventilation, except to provide makeup air for the furnace. The many cracks and crevices around the perimeter of the roof should be sufficient to provide the makeup air, if they are not sealed by foam.

Otherwise, one of the gable vents should be left open, or, if you do not have one, a source of air will have to be supplied. This capital improvement will take a long time to be recouped by your savings, but your comfort and the damage control it will provide should be considered as well.

Your main problem is the cold upstairs. That can certainly be caused by inadequate insulation in the attic, but it is also possible that the new furnace system is not properly balanced.

If you cannot afford to have closed-cell insulation sprayed in the attic, look into having insulation added to the attic's floor. You haven't given me any details on what is there, the depth of the floor joists, what type of flooring, if any, there is, etc., so I can't be offering more accurate suggestions for improvement. If that is the route you want to go, please write again and give as much information as possible.

Q. I will be having siding installed on my house this year, and my contractor prefers to use the black building paper (I think it may also be called black tar paper) as the underlayment for the vinyl siding instead of the Tyvek wrap. My 1950s ranch has that black paper now under the wooden shingles. The old black paper and wooden shingles will be removed. I am also planning on having a half-inch insulating Dow foam board under the vinyl for insulation.

My question is, which paper will be best for insulation, durability and an overall good choice - black building paper or the Tyvek?

A. First, I urge you to consider 1-inch-thick Dow Styrofoam instead of half-inch. The only additional cost you should incur, if your installer is honest, is that of the increased thickness of the material; the installation cost should be the same. But you will recover the added cost of the foam in energy savings, as a 1950s ranch is not well insulated to start with.

There is no reason to remove the old black felt from the sheathing, except that it will be badly damaged in the removal of the wooden shingles. Under ordinary circumstances, I would generally recommend using black felt instead of housewrap, unless the housewrap can be isolated from the siding with one of the methods available to create a rain screen. I have investigated many wall failures with these housewraps in contact with several types of siding. However, extruded polystyrene (XPS) rigid insulation is a hydrocarbon that will be severely damaged over time if it is in contact with the asphalt in the felt. So, in your particular case, you should use Tyvek or another housewrap.

Q. We've had a major problem with a fieldstone fireplace chimney, which has leaked forever. I'm fairly certain it must be in the stones. The flashing has been replaced and runoff on both sides diverted. The roof around this area has been replaced, including the wood. It has been water-sealed several times to no avail. It only lasts for a little while. It now has two coats of KILZ and again leaks.

Would it be feasible to cement the whole thing or repaint? Where do we go from here? Any advice would be very much appreciated. Need to solve this problem before eventually selling.

A. I doubt that the fieldstones are leaking; stones are very dense - unlike bricks - so it is more likely that the leakage occurs at the flashing or the mortar joints. It is possible that the sealant used is the wrong kind or that the mortar joints need tuck-pointing.

A competent stonemason should inspect the mortar joints and the flashings, and make any necessary repairs, followed with the application of a siloxane-based sealer. It would be a shame to stucco the fieldstones.

Q. I have a serious problem at home concerning insulation. My home is approximately 80 to 100 years old, and there is no insulation between the exterior walls and interior walls. I was considering eliminating the plaster and installing insulation and Sheetrock, but the cost would be somewhere from $20,000 to $30,000. So I am going to install vinyl siding with the half-inch foam sheathing underlayment - maybe Green-Guard or Owens brand. Would this be the most economical way out and help maintain the heat inside and the cold outside?

A. If the plaster walls are in perfect shape with no cracks and have been painted several times over the life of the house, consider having cellulose blown into the walls from outside before the new siding is installed. Also consider having 1-inch-thick rigid insulation applied over the existing sheathing instead of half-inch.

If you plan on staying in the house a long time, you should recover the investment in both insulations over the years. And think of your comfort!

Q. My log home was built in 1977. It has a standing seam steel roof with gutters covered with seamless gutter guards. In 2007 and again this year, I have had trouble with ice dams because we haven't had a January thaw lasting long enough for the snow and ice to slide off the shed roof on the upstairs bathroom. The ice only builds up over the eaves.

The roof is well insulated with a tongue-and-groove pine ceiling, R38 fiberglass bats, Styrofoam channels to the roof vent, plywood, 30-pound felt and then the steel roof. However, there is a Broan fan/light in the bathroom ceiling vented out into the soffit. Having read your column over the last decade, I realize this was a mistake, but there is no way to reroute it now because of the building style.

In 2007, the dam got so bad I hired a roofer to go up in February and remove it. There had been ice not only coming from the soffits but also running down the log siding. Last winter and this winter, I covered the fan with plastic, and I don't use it, so little or no additional moisture will enter the soffit from the bathroom. Since the house tends to be dry in the winter due to the wood stove, I leave the bathroom door open when I shower, and then close both the upstairs bedroom and bathroom doors so the heat from the stove doesn't go up there. I had minimal ice problems last winter, but this year, once again, with no January thaw, I have icicles coming out the soffit.

Is this a problem that can be solved by using heat tape on the lower part of the roof and over the gutter guards, or is there another way to stop the ice dams from forming? I would appreciate any advice you may have to offer.

A. I would not recommend using heat tapes; they are expensive to run, need to be managed and have been responsible for fires. You mention a "roof vent." That is not common with standing seam roofs, as many installers do not know how to build one that works effectively. From the photos you sent me, I can see that you have quite a problem. My guess is that the roofer not only did not install an ice-and-water guard membrane on the entire shed roof but also did not caulk the seams of the roof panels, which is why you have snowmelt backing up into the soffit.

It looks as if the wood-stove chimney may be the cause of snowmelt from the roof. Unless the space between the stove pipe and the brick chimney is well insulated, it is likely that the heat loss through the bricks may be aggravating the problem. Unfortunately, the sloped ceiling means that you have no attic space in which to insulate the brick chimney on the second floor, but granular insulation that masons use for the purpose can probably be poured in the cavity between the stove pipe and the brick chimney. See if that helps.

If that is not enough to reduce, or even eliminate, the snowmelt and ice dams, another way to approach the problem is to staple 6-mil plastic to the existing bathroom ceiling paneling, fasten 11/2-inch-thick rigid insulation over the plastic and cover it with new paneling or drywall; it looks as if you have the headroom to do so.

The bathroom fan and the heat lamp will always be a problem. There is a way you can do something about both of them. You can build a chase on the ceiling alongside one of the side walls and install the fan in it.

The fan's discharge can be done through the front wall of the dormer. If you decide to do that, spray foam into the present duct to fill it. Can you also do away with the heat lamp and use another form of heat, or relocate it in the new chase for the fan, setting it at an angle to get its benefit?

The rest of the roof looks quite good. The only snow melting visible is on the south side where the sun's heat bounces off the dormer's siding.

• Henri de Marne's column appears Sundays. He 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 e-mail at henridemarne@gmavt.net.

© 2009, United Feature Syndicate Inc.