Mold
Most mold issues in crawl spaces are caused by high moisture and humidity.
Mold Spores
Mold spores, odors, humidity and critters create a very unhealthy environment for people. Many people are allergic to these things and experience a host of symptoms and don't realize their dirt crawl space is affecting their health.
Natural Airflow
Natural airflow in a house is from bottom to top. This sucks the moist air and everything in it up into the living areas of the home.
Bugs and Critters
Dirt crawl spaces are great places to live, thrive and reproduce if you're a bug. There is an even temperature, moisture, damp wood and shelter. Spiders, beetles, centipedes , termites and all kinds of other insects are found in dirt crawl spaces.
Damp Environment
A damp environment is very unhealthy and destructive. Mold thrives and reproduces by producing airborne spores by the millions and some molds are toxic.
Mold
Mold spores,the seeds of mold, are in the air everywhere. All they need to grow is organic material such as wood, the right temperature range and moisture. Of these, the only one that can be controlled is moisture.
High Humidity
Dirt crawl spaces have the high humidity levels necessary for mold growth. Humidity levels from 50- 90% are easily found in dirt crawl spaces that have never flooded.