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How to Cure Indoor Condensation Problems

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Moisture can cause significant damage to both cosmetic and structural elements of your home. It can also breed mold and mildew, which can be harmful to your health. Help reduce condensation with these simple tips.

Causes of Condensation

Water can form anywhere cold air meets hot air. The cooler the room, the less it's able to absorb water vapor, so heating a room decreases the potential for condensation. However, water will condense on cold surfaces, such as uninsulated exterior walls and windows inside heated rooms. As the air nears or touches the surface, the decrease in temperature robs the air of its ability to hold water, and droplets form on the cold surface.

Even insulated walls or windows can experience condensation as a result of a cold bridge—or when a solid element that extends from the cold outside air into the warm air inside, transfers the cold with it.

Condensation often forms first on glass and rapidly on uninsulated windows, which are the only barrier between the heat inside and the cold outside. It accumulates into drops, which run down into the wooden components of the window, causing mold and rot. The potential for this problem can be reduced by adding storm windows or sheet plastic barriers to the outside of the window.

Modern, double-glazed units could also replace single-pane windows. Double-glazed windows have two panes of glass, which are usually separated by a sealed space that contains an inert gas. With this type of construction, the glass is insulated from the thermal extremes imposed on a single pane, thereby reducing the potential for condensation.

If dealing with serious condensation or mold problems, consult a professional before repair costs mount.

3 Ways to Control Humidity

  • Provide Proper Heating

Dry heat will reduce humidity, decreasing the potential for condensation. Be aware that heating with kerosene heaters can make condensation problems worse. The process of burning kerosene creates water vapor, increasing the moisture level in the room and increasing the chance of condensation forming on walls, windows or any element that conducts cold into the heated airspace. It may be necessary to use an alternate form of supplementary heating if you experience condensation problems.

  • Provide Adequate Ventilation

Unlike older houses, today's super-sealed and insulated homes are often airtight. This can create condensation problems by reducing air exchange. For this reason, providing adequate ventilation becomes a priority in situations that generate moisture. A lot of moisture is generated during hot showers and baths—and it goes straight into the air to await an opportunity to condense on an obliging surface. Bathroom exhaust fans are relatively simple to install and constitute the front line in the battle against bathroom-related moisture problems. Also, all gas burners and clothes dryers should be vented to the outside.

  • Use a Dehumidifier

If high humidity is a problem that can't be overcome by heating or ventilation, use a dehumidifier to reduce the potential for condensation by directly removing the moisture from the air. Dehumidifiers are rated by the maximum amount of humidity that they'll remove from the air in a 24-hour period. Dehumidifiers are commonly used in laundry rooms, basements and bathrooms along with any room that isn't air-conditioned or has poor air circulation.

Other Factors

Proper Installation of Insulation

  • Insulation that blocks and prevents ventilation in an attic can also result in condensation, creating a condition that fosters mold in the framing elements of the house. This can affect your home's structural integrity. Make sure air can circulate freely through the attic space. Don't cover eave vents with insulation, and adequate air passage through ridge vents, gable vents or turbines must be maintained.

Potential Pipe Problems

  • Uninsulated pipes pose potential problems. Warm air contacting cold pipes causes condensation to accumulate on the pipe. As it accumulates, it runs and drips, creating a moisture problem. Pipes can be insulated with preformed sleeves that have a slit down their length and just snap in place on the pipes. Cut them to length to fit as closely as possible at all ends, corners and junctions. With a little imagination, you can cut miters and angles in the material in such a way that the insulation completely covers any junctions. Cover the slits and joints with vinyl duct tape.

Fix that Fireplace

  • A sealed fireplace can create condensation problems. If air can't circulate in the fireplace, condensation can accumulate on the walls and be absorbed into the masonry. If you decide to seal a fireplace, include a vent at the bottom in the material you use to seal the opening, and provide a means at the top to allow air to escape without allowing rain to enter.