I have a newly constructed home with a full basement...half below and half above ground. I have no visible water anywhere in the basement however I am seeing mold and mildew growing in the basement and even some places upstairs. I did the aluminum foil test and there was no condensation on either side. We also run a dehumidifier downstairs and that fills in less than a day.

The house was built last fall and we had 11" of rain during the 1st part of construction. The basement was obviously laid up on very wet ground. Would have anything to do with a moisture problem a year later?

Is the moisture in the basement likely causing the mold upstairs? Will waterproofing the basement walls help?

 

Mold & mildew require heat & moisture to grow. IMO waterproofing the basement is a good place to start. I've never needed a dehumidifier but it sounds like it is removing a lot of moisture from the air. I don't think the rain a year ago would have a long lasting effect. Moisture acumulated during construction is usually gone after a month or two of running heat/air.

 

It is filling up in less than a day and is sometimes hard to keep up with. It wouldnt be such a problem if we had a floor drain but we dont.

Are there any other solutions to such a problem?