When dry means: feels dry, smells dry, and looks dry in your basement...
Just because you have a waterproofing system, doesn’t mean you have a dry basement. Confusing, we know. Bear with us, this is important:
There are 4 ways basements become wet or damp:
Whenever the outside air is warmer than the inside air, and especially when its humid outside air, we are likely to have a condensation problem in our subterranean levels. This is because the Relative Humidity of air goes up 2.2% for each one-degree(Fahrenheit) you cool it. Our basements are always cool because they are below ground. And we know that a house is like a chimney- air flows upward, allowing air to escape the upper levels, with new air being sucked in at the lower levels.
If it’s an 80 degree (F) day with RH of 80%, and we suck this air into our basements and cool it to 68 (F) degrees, the RH goes up by 26.4% (12 degrees (f) x 2.2%). But wait a minute, 80% plus 26.4% is more than 100%, and we can’t have more than 100%. So instead, as the air becomes saturate it gives up its moisture on your cold basement walls, floor, water tank, pipes, and other cold things. This is called condensation.
Even without condensation, we still get high relative humidity levels, which allows mold to grow and cause “stinky basement syndrome.” And dust mites are having a party.
In order to eliminate condensation you need to either heat the basement (ridiculous in summer), or take water out of it (easy to do).
Correction; take the water out of it efficiently and effectively (not so easy unless you have the right equipment to do it with).
So what is the answer?
An excerpt from: Dry Basement Science by Larry Janesky