As you know, excessive humidity, whether in your crawlspace, basement, or attic can lead to serious problems for both your health and that of your home.  One of the most serious problems for homeowners is what is referred to as "wood rot".  The actual microscopic organisms that cause wood to decay belong to the fungi group.  Wood rot is often called dry rot.  This is an oxymoron because wood needs moisture to decay.

The 3 Major Components of Wood: Cellulose  40-50% Hemicellulose  25-40% Lignin  20-35% For fungi to be able to colonize on wood there are 4 requirements that must be met: Adequate supply of oxygen Temperature range between 40-100 degrees Fahrenheit Constant source of moisture Food supply (the wood itself)

The wood in your home "decays" because the fungi actually eat the cellulose, hemicellulose and lignin that wood cells are made from by releasing enzymes that digest specific wood components.  The fungus thrives in warm, moist environments such as crawlspaces and basements with steady supplies of moisture.  Not only do you risk wood decay but also possible expensive foundation water damage repair.  This is why controlling moisture is so important!

Did you know that… according to the National Association of Waterproofing and Structural Repair Contractors (NAWSRC) untreated moisture damage can cause a deterioration of your property value by 10 to 15 percent?!

Once you have discovered wood rot, the most important thing to do next is to determine where the home moisture is coming from.  Look for the obvious first; roof leaks, plumbing leaks, gutters and downspouts filled with debris, poorly graded soil that slopes toward the foundation and cracks in the foundation.  It’s also a good idea to check windows to make sure they are properly sealed.  You should maintain caulk around all of the seams and look for swelling of windows or peeling paint.

If your house has a crawlspace, you should look for puddled water and water or mold stains on foundation walls.  If you determine that excessive moisture is coming from the crawlspace, you should install a vapor barrier and a superior crawlspace dehumidifier.

How is your crawlspace growing mold while three seasons out of four, your home feels comfortable and dry?  Sure, it may feel rather humid on the occaisional summer day, but most the time the house feels fine…  So how does your crawlspace trap humidity?  Even with your vapor barrier, moisture will condense and breed mold, termites, dust mites and more.

Here’s the answer.  Air in your crawlspace is always more humid than the air in the house.  And this is because cool ground temperature keeps the crawlspace colder than the air in your house.  Because of this temperature difference, your home’s living areas can feel dry, while below, crawlspace humidity runs rampid.

Here are a couple terms to know:

1. Dew Point = Temperature at which water vapor condenses
2. Relative Humidity (R.H.) = % of moisture present in relation to of moisture the air can hold.

In other words, relative humidity is the percent of water in the air.  When R.H. hits 100%, water will condense, rain or snow.  Dew Point is the temperature when this happens. Here are a few scenarios to show what happens in your home and crawlspace during typical weather conditions.

NOTE: Crawlspace R.H. (relative humidity) should try be 40% or less in order to keep Dew Point around 10-15 degrees below the crawlspace temperature.  EPA recommends 40% – 50% R.H.  This will control dust mite and mold populations.  A crawlspace dehumidifier should always be used during humid or rainy weather.  Humidity in the living area above, can be as high as 50% or 60%, based on comfort.

As the winter air enters, the humidity drops slightly within the crawlspace.  Notice relative humidity is 62%, beyond what the EPA considers acceptable.  As the air migrates upward, it warms greatly and relative humidity drops drastically.  The house feels dry, but the crawlspace still requires dehumidification.  To control dust mite populations, it is recommended that the crawlspace be kept at 40% R.H. all year long.  Unfortunately, most dehumidifiers will not work at a 45° temperature.  Though, our Dri-CrawlSpace^® dehumidifiers will run just fine all the way down to 33°.

Still winter time, but here we have a cold rainy day.  It will still feel dry indoors, but notice as the outside air enters the crawlspace, relative humidity only drops to 70%.  During this type of weather, your crawlspace dehumidifier should be running.  Be sure to choose a Dri-CrawlSpace^® Dehumidifier because it is one of the few that can operate in temperatures this low.

This is the type of weather where mold really thrives, especially if it were to rain.  It’s too cold to run the air conditioner, so high humidity goes unchecked.  If it were raining, relative humidity outside would be 100%.  This would raise the dew point to 55°.  With the crawlspace at 58°, humidity would rise to a whopping 89%.  All your cold water pipes and exterior walls would be dripping wet.

Here’s a nice warm day with comfortable 50% humidity. But because it is so warm, dew point is also going to be warm.  Any surfaces below 60° will form condensation.  Look how high the relative humidity gets as the air cools to 65° in the crawlspace.  At 83% relative humidity, your crawlspace is sure to grow a good amount of mold, as well as make a fine home for spiders, termites, cockroaches and other pests.

The mild summer night is the worse case scenario for allergies. As temperatures near the dew point, dust mites and mold will multiply and run rampid throughout your home.  Notice how quickly food goes bad in this weather.  Also, if you notice more bugs in your home,  these are indications of high humidity.  A good crawlspace dehumidifer like the Dri-CrawlSpace^® can keep up with these humid conditions and make your home comfortable while taking some strain off your air conditioner.

For more information on crawlspace dehumidification, sign up for a FREE REPORT that reveals 7 Things You Should Know Before Buying Any Crawlspace Dehumidifier.