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5 Signs You Need a Dehumidifier

A Little Humidity is Fine, But Too Much Can Lead to Big Problems

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For health reasons, it's important to maintain a proper humidity level in your home.  While too little humidity can cause some discomfort issues such as chapped lips as well as cracks in wooden furniture, the reverse side of the coin - too much moisture, can make your home a breeding ground for mold and mildew, which can lead to some very serious health issues. A dehumidifier can help you remedy excess moisture problems.

You can more accurately measure your home's humidity level with a hygrometer and then take appropriate action to either add humidity with a humidifier, or remove moisture with a dehumidifier.  While a hygrometer is a very handy instrument for controlling home moisture, there's a tendency to only measure certain living areas, thus omitting some corners where moisture problems can take hold.  Learn how to recognize signs of excessive moisture and take action immediately, to ensure safe and recommended moisture levels are always maintained.

Some homes may have moisture problems only at certain times of the year, such as in Spring when there is a lot of ground water runoff, while other residences need help to control moisture levels, year round.  There are also times when moisture is a problem only in one room or area of the home and though small, this should not be neglected.

Once excessive moisture is detected, the first plan of action should be to discontinue any use of humidifiers if these are in use, or to try and remove what is causing the humidity.  Further action should be taken to find the cause and remedy the situation.  This article will help to alert you to the most common signals when excessive humidity is present and a dehumidifier is required as part of the action plan.

1. Window and Patio Door Condensation

Steam from humidifier, close-up
Keith Goldstein/The Image Bank/Getty Images

Condensation on the interior glass, water beading on a window or the presence of what looks like a fog or vapor on the glass are typical signs that there is too much moisture in the room.  This often happens when a humidifier is too large for the room and puts out too much humidity.  A build-up of moisture on a window sill can eventually rot wooden casings and that wetness will allow mold to grow.  Mold will look like a black or dark grunge on the bottom window trim, or in the track of a patio door.

Immediately turn off any humidifier that is operating and in future, downgrade the unit to reduce the amount of moisture output.  When too much humidifier output is the cause, the moisture level may correct itself simply by stopping humidifier use and opening a window to add air circulation to the room.

Other things that can cause a moisture buildup on windows is humidity present in the construction materials of the home such as with improper sealing of sheetrock walls or humidity that is present in cement. The outdoor climate can also cause some indoor moisture problems, such as when it rains for several days or the area where you live has a high humidity factor.  A dehumifier will effectively remove the moisture from the home and restore proper indoor levels.  Remember to rotate the dehumidifier through all the areas affected by excess humidity.

2. Mold Spots on Ceiling or in Corners of Walls

Because steam rises, bathroom moisture problems are often found on ceilings or up in the corners of the walls.  Bathrooms that do not have efficient fans to divert steam and humidity to the outdoors, most often have some problems with mold.  Mold can grow on wall, ceiling, under/around the toilet or behind the bath or shower surround.  A leaky toilet or plumbing can also cause moisture problems. Excess moisture can cause black mold to grow, which can in turn cause serious health issues.  You don't have to see the mold for it to affect you; it just has to be present somewhere.

Running a dehumidifier in these areas can help, but remember that while this is necessary, you have to get at the root of the problem to find a longterm solution.  A dehumidifier will lessen the amount of moisture damage but the cause cannot be ignored.  For those finding a repair solution for excess moisture such as removing mold and repairing walls, you must use a paint that is specially formulated to resist mildew and seal those areas which have been repaired.  Otherwise, mold will find its way back through layers of regular paint and be noticeable once again.

Other areas of the home often affected by trapped moisture are closets, garages or basement rooms and storage areas.  You might also see dripping or mold spots below windows.  This can be caused by faulty window seals or rotting casings.  In this case, windows should be replaced along with frames and sheetrock and insulation changed to remove all wet areas.

3. Musty Smell or Odor

The presence of a musty odor in basements, crawl spaces, entrances and garages signals the presence of mold and mildew. Moisture could have been one-time event or a recurring problem. Possible causes range from improper window/door seals, construction sealing issues to wet basement areas from high ground water seepage, which can be a natural occurrence in your particular locale or by inadequate weeping tile installation around the home.

Anytime there is a musty smell, there's mold somewhere and that's not healthy for anyone.  A dehumidifier can help with immediate moisture removal, but you'll have to investigate further and remedy the situation to not have recurring problems. In all likelyhood, those areas will also require heat to help dry the affected space.

In the laundry room, a musty odor in the air, or musty smelling towels or bedding could signal problems with an HE or front load washer.  Though more efficient in many ways compared to a traditional top load washer, many front loading washers tend to have mold issues.  There have been many advances by manufacturers to reduce the risk of mold in front load washers since they were first introduced to the market, but consumers need to know that it can still happen - regardless of brand. 

Mold issues are not specific to a particular brand, though some washers have been redesigned and are better than others.  Learn the differences between a top load washer and a high-efficiency front load washing machine and what you need to do to avoid mold issues.  Consumers have left many helpful comments with solutions on how to deal with front load washer mold.

A musty odor in the laundry room can also be caused by a plugged exterior vent or an interior dryer lint filter that has been neglected and is impacted with lint.  This can cause moist air from within the dryer when drying a washload, to become trapped since there is no clear, unobstructed air flow, resulting in a musty smell.  Plugged lint filters in or outdoors, can also become a fire hazard.  They should be cleared of lint - the interior dryer lint filter should be emptied after each dryer load; the exterior lint filter should be cleared as required.

4. Recurring Spring Water Run-Off Dampness

If Spring ground water dampness has become a recurring problem or you have purchased a home that has white or grayish water level marks in the basement, you need a dehumidifier on hand to remove the extra moisture should these events occur. It would also be a good idea to investigate why your basement is prone to water which may be from inadequate weaping tiles around the home, concrete that needs to be reparged and sealed, or it may simply be because the house was built on a historical river bed or low plain.

5. Buying a Home? Inpect for Mold, Water Stain Marks

Whether you're buying a home or RV, you should always look for signs of excess moisture problems, which may require corrective action and can also become an annoyance and health concern, if it proves to be a recurring issue.  Tell tale signs that a home has had water problems are mold or mildew in corners of walls, bathroom ceiling/walls and water level marks in the basement.

Look inside closets at the walls, behind furniture at baseboards, around and below windows for evidence of mold or water stain marks and be on the lookout for musty smells.  It's not uncommon for some people to give their home a fresh coat of paint to mask potential problems, when it goes up for sale.  That can make it harder to detect water problems, but looking inside closets and inspecting the foundation and basement can be worth your while.  A home that is overly fragranced often has something to hide when it comes to odors or mold.

If you do encounter noticeable water problems, be sure to ask why and if remedial action was undertaken. You may want to bring in an expert to confirm or allay your fears and give you an estimate of possible costs to remedy the situation.

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