Sweaty house no laughing matter
Q: Our three-year-old, 3,000-square-foot house is sweating on the inside. The windows, the sheet-rock walls and some of the ceilings are dripping moisture. We are temporarily controlling this with a dehumidifier. We would like to know if there is a more effective or permanent way to control this problem.
It is a wood frame house with vinyl siding and 1/2 -inch Styrofoam under the vinyl. The overhang is trimmed with soffits in which every other piece is vented. The roof is asphalt shingles with a continuous vent across the top. Inside the walls are 3 1/2 inches of R19 insulation, and the attic has 6 inches of R30 insulation. If you have any suggestions we could use, we would appreciate it. — Everett F., via e-mail
A: First, it’s great that you’ve taken emergency measures so quickly to control the high humidity levels inside the house. Left unchecked, all that moisture in the walls and ceiling can lead to a serious mold problem. Second, finding the source (or sources) of the humidity and resolving the problem is a priority, and one you most likely need professional help with.
Humidity is constantly generated inside houses from a number of sources: daily showers, laundry and cooking, for example. In fact, a family of four can generate five pounds of water vapor in the home each day! All that moisture has to go somewhere, and if it can’t exit the house, it will condense and drip down the ceiling, walls and windows.
To resolve this problem, you need to re-check the insulation and venting in the attic and along the roof, as well as the wall insulation, to ensure that vapor barriers were installed correctly. And, if you have a basement or crawlspace under the home, check to see if foundation vents were properly installed.
Look at other venting in the home, including dryer vents and stove exhaust fans (which should always be vented outside, not into the attic). If there are no exhaust fans in the bathroom, kitchen or laundry room, install them. Even small measures can make a difference, such as covering fish tanks and emptying radiator or refrigerator water pans frequently.
If your home has a lot of plants clustered together, move them so a few feet of space exists between each. If you have a fireplace, open the damper in winter to allow a free exchange of air. And, until the problem is resolved, keep running your dehumidifier and open two or three windows in the house — just a crack — to allow more moisture to escape.
Since your home is only three years old and the excess moisture presents a serious mold risk, resolving the problem and repairing any damage may be covered by warranty or insurance. Review options with your insurance representative.
HOME TIP: Excess humidity inside the home (greater than 30 percent to 40 percent) can cause mold, which presents a serious risk to both the home and family health. This problem needs immediate attention.