How dangerous is off-gasing from polyethylene plastic sheets?
Using a 10ml sheet in old basement to cover the dirt areas to retard moisture. 1929 yr old house w basement built into dirt hill. Using dehumidifier now.
If you can place 6mil sheets of visqueen and cover it with 2-4" of concrete, this is the best method to remove moisture intrusion into the home if you intend to use the basement.
If you are not using the basement you can cover the plastic sheets with 4" of dry sand. Over time the sand will retain moisture and you will have a musty smell again.
For more information:
Read "Moisture is leaking through our new basement windows. What should we do?" a Q&A answered by Greg Upwall.