Vinyl Siding Causing Condensation on Inside Walls

Identification

• Condensation begins on the inside of your home, when heated indoor air meets cold air near your walls or windows. The cold outdoor air causes excess moisture to adhere to your wall in the form of condensation. This a common problem during the winter, because warm air holds more water vapor than colder air. When condensation is visible on your walls or windows, it means you have a moisture problem inside your home. Indoor humidity levels higher than 40 percent during the winter months is a common cause of condensation. Air leakage and inadequate amounts of insulation are also common causes of condensation on interior walls. Vinyl siding with gaps in coverage or siding with damaged areas may allow air to seep into your exterior walls, reducing the temperature close to the interior wall which increases the likelihood of condensation.

Effects

• Frequent condensation can cause discoloration and staining on your interior walls. Any time moisture is present inside your home, mold may begin to grow. Mold spores can begin to germinate in as little as 24 hours after landing on an area of moisture. When mold growth occurs, you and your family may experience adverse health effects, such as sneezing, nasal congestion or skin rashes. Those with respiratory diseases or those who have deficient immune systems may experience severe symptoms, such as wheezing and difficulty breathing. Your interior walls may require repair when mold is present because mold eventually digests the materials it grows on.

Solutions

• Reducing the humidity levels in your home may help keep condensation from forming. Running a dehumidifier may reduce indoor humidity. Installing exhaust fans in humid rooms, such as your kitchen and bathrooms, is another way to lower indoor humidity. Installing adequate amounts of insulation in your walls may also help reduce condensation. Loose insulation is often blown into closed areas, such as walls or ceilings with special equipment. Inspect your interior walls for signs of mold growth. If you notice dark gray or black splotches of mold or mildew on your walls, you must remove it to avoid health problems and costly repairs. Scrub mold away with water and liquid dish detergent. Rinse and dry thoroughly. If your walls are stained from mold growth, try using chlorine bleach and water to reduce staining.

Prevention

• Sealing all air leaks can prevent condensation from forming on your windows and walls. Air leaks are common underneath window sills where the drywall begins. Seal all gaps with caulk to keep cold air from leaking into your home and causing condensation. Closely inspect your vinyl siding for gaps where cold winter air could leak through your exterior wall. Replace any siding with damage or gaps to prevent condensation.