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Damp is a common problem for many homeowners, especially during winter months when the temperature outside is far lower than inside. Condensation is the most common culprit of excess moisture but damp can also be a result of poor ventilation and activities like cooking, doing laundry, and bathing. Don’t worry, the presence of damp doesn’t mean you’ll automatically get mold—just take care of the excess moisture as soon as you can to prevent costly repairs down the line.


[Edit]Preventing Condensation

  1. Keep the inside temperature as constant as possible. Condensation occurs when warm air touches cold surfaces, so try to keep your home around the same temperature as much as you can. Keep your bedroom 61°F to 68°F (16°C to 20°C) and the rest of the house 66°F to 72°F (19°C to 22°C). When you’re not home, make sure the temperature stays above 59°F (15°C).[1]
    • For example, don’t alter your thermostat to be extremely cold during the day and hot at night or vice versa.
  2. Use a dehumidifier in your kitchen, bathroom, or basement. Dehumidifiers take moisture out of the air, so it’s best to place them in areas that collect the most moisture. The capacity of the dehumidifier you’ll need depends on the size of the room and how much moisture is in the space. For instance, a 30-pint dehumidifier will work for a slightly damp (50% to 70% humidity) room about 300 square feet (28 square meters) in size.[2]
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    • For a moderately damp (60% to 70%) area of 1,500 square feet (139 square meters), a 70-pint dehumidifier is a good choice.
  3. Wipe down any surfaces that are prone to moisture. Use a dry rag to wipe window sills, window panes, and countertops where moisture might form and settle. Moisture is more likely to show up near your windows in the winter when it’s warm inside and chilly outside.[3]
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    • If you have double or triple-paned windows and notice fog or moisture between the panes, it’s a sign that your windows need to be replaced.
  4. Avoid home improvement projects when it’s cold outside. If you’ve planned to paint your walls or do a deep clean that involves mopping, wait for a day when it’s over 50°F (10°C). Wet surfaces dry slower when it’s chilly outside, which can end up creating excess moisture.[4]
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    • Save painting and cleaning for days when you can comfortably open a window to prevent trapping air and causing condensation.
  5. Dig away any soil that’s resting against your home. If your home has dirt resting around the outside perimeter, use a small shovel to move the soil away from the side of your house. Dig a small trench at least 6 inches (15 cm) deep to prevent moisture buildup.[5]
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    • Moisture travels from the soil through porous materials (like concrete slab) through a process called capillary suction.

[Edit]Improving Ventilation

  1. Move furniture away from external walls to increase airflow. If you have a couch or chest pushed directly against an external wall (that is, a wall that insulates your home from the outside), reposition it so there’s at least 6 inches (15 cm) of room between the back and the wall. The extra space will allow air to flow between the furniture and the wall, preventing trapped air from causing condensation.[6]
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    • If possible, reposition any large furniture pieces to be against internal walls instead.
  2. Turn on extractor fans whenever you’re cooking or bathing. Most stove setups have an extractor fan on top that draws in smoke and steam and pumps it out through another outside vent. For bathrooms, it’s usually located in the ceiling above or near the shower and you use a light switch to turn it on.[7]
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    • Be sure to clean your inside extractor vents by wiping them with a rag dipped in soapy water.
    • Closing the door to the kitchen or bathroom will also keep moisture from spreading to other rooms in the house.
  3. Crack open 1 or 2 windows for at least 15 minutes a day if possible. Open a window or door (ideally located on opposite sides of your house) to bring in some fresh air. It’s okay if you can’t vent on opposite sides, just open 1 or 2 windows or doors to allow moist air to escape.[8]
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    • However, if you live in a hot, humid environment, it’s best to rely on the air conditioner and a dehumidifier.
    • As an alternative, leave your ceiling fans running during the day or at night while you’re sleeping.
  4. Put lids on saucepans when you’re cooking. Cooking releases tons of steam into the air, so put a lid on your pots to keep as much of the vapor in the pot as possible. If the recipe calls for leaving the lid off, be sure to turn on the exhaust fan or, if you don’t have one, a ceiling fan or small electric fan will do the trick.[9]
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    • Cracking a window will also help keep the moisture level down when you’re cooking.
  5. Don’t hang dry clothes indoors or over radiators. Hang-drying clothes can drip water onto the floor and raise the moisture in the room by as much as 30%! It’s best to use an outdoor clothesline, but if you must dry clothes indoors, hang them near a heating vent, extractor fan, or regular fan to increase the drying time.[10]
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    • If you have a dehumidifier, place it in the room where you hang-dry your laundry to minimize the moisture in the air.

[Edit]Checking Your Home for Moisture

  1. Use an electronic moisture meter to check your walls twice a year. Set the moisture meter to the correct mode according to the material of your walls (e.g., wood, stone, brick). Hold the back of the device against the wall to take a reading. Lift it up and move it to another area of the wall (don’t slide it). Do this several times on each wall in the center of the wall and in areas most prone to moisture (like around windows). A reading of over 20% means you have a moisture problem.[11]
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    • If your moisture meter has pins, insert the pins into the wall as far as they’ll go to take a reading. This isn’t ideal since you’ll have to put small holes in your wall.[12]
    • Note that metal mesh or studs in the walls can cause false readings, so try to measure away from areas with metal if possible.[13]
    • Your moisture meter may also have “green,” “yellow,” or “red” icons, which can tell you if the moisture is in the proper range (“green” meaning a-ok and “red” meaning there’s too much moisture).
  2. Scan the pipes in your home for signs of leakage. Feel the pipes in your home for any signs of moisture. You should also look at the area around and under the pipe to see if there are any pools of water or signs of dripping.[14]
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    • As an alternative, find your water meter and write down the reading. Don’t use any water for 3 to 4 hours and check the reading again. If the reading has changed (even by a little) that means you have a leak somewhere.
  3. Look for signs of mold on your walls and ceilings. Mold can look like specks of dirt or soot on your walls and ceilings. It can be blue, grayish-brown, or dull gray-green in color. Be sure to check around air vents, window moldings, and doors where mold is most prone to grow.[15]
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    • If you see visible mold, you may need to call a professional because there could be more mold colonies growing inside the walls.
  4. Notice any signs of water damage or off-putting smells in your basement. If you have a basement, look around for standing water, deteriorating wood, rotting columns, stained or blistering walls, condensation on the walls and ceilings, and leaks. If you notice a stale smell of mold or mildew, there’s a big chance you have damp.[16]
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    • Moisture can travel up from your basement, so don’t think the other floors are damp-free if your basement has lots of moisture.
  5. Inspect all the wooden parts of your doors twice a year. Make sure your doors and their frames are free of moisture by inspecting them with your eyes and hands. Use a screwdriver to poke the wood in several spots, making sure it’s hard and not spongy.[17]
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    • Be sure to check the threshold, jamb, and trim as well.
    • Checking your doors is especially important if the door doesn’t have a roof overhang to protect it from rain.
  6. Climb on top of your roof to check the shingles for signs of damage. Cracked roofing can be a source of hidden leaks. Use a ladder to get onto your roof and check the shingles for any cracking or buckling—all the shingles should lie flat against the roof. Try to jiggle them with your hands to make sure they’re all sturdy because a loose shingle could be the cause of leakage.[18]
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    • While you’re up there, you may want to inspect the gutters for any signs of granules that may have come off the shingles. Losing granules is a sign you may need to replace the shingles soon.
  7. Listen for sounds of dripping water coming down your chimney. Heavy rain and storms can cause structural damage to your chimney’s cap or flashing (the seam between your chimney and roof). Sit near your fireplace to see if you can hear dripping sounds and use a flashlight to look up the chimney to check for moisture stains or wetness.[19]
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    • Lots of rain can also damage your chimney’s bricks, which is a much larger problem. If you see any cracks or dislodged bricks, call a professional to have it fixed.
  8. Examine the inside of your windows for condensation. It’s normal for condensation to form on the outside of windows, but if you see any moisture forming on the inside of the glass, you may have a problem. Look at your windows and sliding glass doors to see if you can detect any moisture. You might see vapor fog or water droplets streaking down the glass.[20]
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    • Be sure to check the glass around the edges of windows or doors because this is where the first signs of a moisture problem will start to show.
  9. Notice if any wallpaper is peeling. Wallpaper that’s peeling or starting to peel from the wall can be a sign that vapor has gotten behind the wallpaper and weakened the glue. It may also cause the wallpaper to bubble outward from the wall.[21]
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    • Look to the top and bottom corners of wallpaper where peeling and bubbling are more likely to happen.


  • If you plan to redecorate, look for moisture-resistant paint and wallpaper to prevent moist air from peeling the paper.[22]
  • Don’t install carpeting or use rugs in areas that are prone to moisture buildup because the material will trap the moisture and may lead to mold.[23]


  • If you discover mold in your home and you have asthma or start exhibiting signs of asthma, call a professional to clean it up.[24]




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