Basement and Crawl Space Humidity

Why are basements and crawl spaces notorious from being damp, humid spaces? If your basement is not flooding or leaking from the pipes, where is all that moisture coming from? The answer may surprise you.

Moisture enters your below-grade space through the concrete- even when the concrete's surface looks dry. The fact that moisture can pass continually through concrete makes sense- if concrete was watertight, it would never cure after it was poured.

As the moisture makes its way to the surface of the concrete, it's pulled into the air, adding to its relative humidity level. As it does so, it may leave a white, powdery substance on the basement walls, known as efflorescence.

The Stack Effect

The way air moves throughout the home is known as the "stack effect". With the stack effect, warm air moves upwards through the home. This heated air will rise upwards until it reaches the top floor and attic, where it then leaves the house. Simple.

As air leaves from the upper floors, it pulls air upwards from below, including from your basement and/or crawl space. The end result is this: whatever is in that air- including humidity- will also be in your home.

If you have crawl space vents, the problem becomes even more serious. In the summer, humidity can flow into the crawl space from the outside air. Instead of flowing out through the other vents, however, this air is pulled upwards into the home to fill the vacuum caused by the stack effect. Crawl space vents simply do not work.

Crawl Space and Basement Humidity in the Home

Here's what high humidity levels mean to your home:

Higher Utility Bills
Humid air takes more energy to heat than cool air. And air conditioners spend much of their energy dehumidifying the air. If your crawl space or basement is filled with humidity, then your home will experience higher utility bills as well. Of course, if you have crawl space vents, you can also imagine what the winter's cold flowing into your home is doing!

Musty Smells
Humidity leads to mold, dust mites, rot, mildew, and insects, and these things lead to odors. If you have foul smells in your basement or crawl space that are wafting up into your home, you can be sure the culprit is humidity. With mold spores and dust mite waste at the base of these odors, you have much more than an unpleasant smell to be concerned with.

House Mold
House mold is a growing problem in homes across the United States, Canada, and the United Kingdom. A home with high levels of mold can hold thousands of mold spores in a single cubic meter of air, and the average person breathes in 10 to 12 cubic meters each day! If you're experiencing allergic reactions such as a headache or stuffy nose at home that seems to fade when you leave the house, this may be the reason.

Dust Mites
54,000,000 people in America alone suffer from allergies- an increase of 75% from 1980-2001 alone, according to ICS Cleaning Specialist Magazine. Dust mite waste counts for 80-90% of the allergenic components of house dust and contains 15 different allergenic components. However, reducing home dust mites is a simple task.

Rot and Damage in a Basement
In a basement, mold, mildew, and rot can affect a wide variety of materials. The basic materials in a basement, such as wood, carpeting, drywall, and paint can all become food for mold and rot. Additionally, stored items such as cloth, cardboard, leather, and furniture are all susceptible to this damage.

Crawl Space Rot
Dank, humid air in a crawl space means moist, rotting wood. This will eventually lead to rotting support beams, mold spores, and sagging floors above. In time, your home will become so damaged by this rot and mold that repair will be the only option. Dehumidification is only part of the solution to a humid, moldy crawl space.

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