The basement is a walkout, and to my utter dismay, does NOT have a drain. It does have a sump crock. And not to over-document, but in addition to this new wall issue, the house DOES have a water issue in the basement. The builder did not sufficiently grade the lot, and the lot lies in the ‘low point’ in the subdivision. So there aren’t a lot of places for the water to go. How the drainage was designed to work in this subdivision is still a curiosity to me. During heavy rains, if there is saturated ground, water does back up through the doors in the basement (another issue we are continuing to fight/deal with).
Recently my son has been running a portable dehumidifier in the basement, and it isn’t picking up much water in the air (which I was also surprised about).
He is gone working during the day, but his significant other and two kids are there. The basement is unfinished, so no one is really down there much during the day.