Dear Glenn: We have a split-level home built in 1977 with no problems until the last two years. Since then, we have added more blown-in insulation, new windows and a heat pump. We have also replaced roof vents with two turbine vents. We also installed three eave vents on each side of the house.

After a cold day or night, and a warmer day, the south side of the house sweats moisture under the 12-inch lap siding from one end of the house to above the heat pump and, except for about 6 feet, to the other end of the house. Some areas are worse than others. The house has a thickness of black material under the lap siding, and the walls are insulated with faced fiberglass insulation. What can I do?

Rocky, via e-mail

Dear Rocky: First, get a blower test performed. This will probably tell you that the house is too tight. With all the new upgrades you did to the home, there is not enough combustion air coming in. But you can fix this problem by installing either a Skuttle Model 216, (800) 848-9786, www.skuttle.com, or an Equaliz-Air, (734) 462-1033, www.equaliz-air.com.

Either product will help bring fresh air into the home and cut down on the moisture problem.