Humidity and Your Crawl Space

Your home costs money to operate- specifically heat, cool, and maintain. Amid the summer heat, it costs even more to cool and maintain. You can’t tell from that outside that your home is costing you extra money in heating and cooling costs and that it is rotting the house from the inside out. The moisture comes from 2 sources: the ground and the outdoor air.

Standing Water

Groundwater leaks cause humidity in your crawl space. It often enters under the footing, between the footing and the walls, right through block walls and through cracks in poured walls. After it seeps in, lies there in a puddle, slowly evaporating upward into the house.

Crawl spaces often have poor or nonexistent exterior footing drains and no damp-proof or waterproof exterior wall coatings.

Moisture from the Ground

Exposed earth contributes a lot of water and vapor into the crawl space air.  When the exposed earth is damp, the water vapor trapped moves upward. In most climates where there are dirt crawl spaces, you can never dry the earth, and this invisible stream of water vapor from the exposed earth in a crawl space goes on forever.

The average temperature of the ground in your area is the same as the average annual outdoor temperature of your area. Whatever that number is, clearly is less than the temperature of the air that enters your crawl space in the summer.

An Open Vent

Air is an efficient way to move water. Air, including humid air, moves easily in and out of spaces. It is all around us and moves in vast quantities through the largest and smallest of spaces. It brings moisture content with it wherever it goes.

What Could Humidity Lead to?

• Damp wood- rotting and mold growth
• Wet Air Ducts- with the air conditioning on
• Wet Joists, Girders, Sill Plates, and Insulation- Porous material will soak up moisture from the air like a sponge.
• Sticking upstairs doors and windows, and smelly carpet
• Increased heating/cooling bills
• MOLD!

All these wet surfaces in a crawl space will eventually have to dry, and the moisture will have to go somewhere else.  Give Healthy Spaces a call if your crawl space has any of these unhealthy symptoms.