Just bought a new townhouse in September. The basement area is small because it's not the full footprint of the house. About half of the basement is above grade. My husband has a 120 gallon fish tank and a
40 gallon in this room. The back wall of the basement is insulated with fiberglass insulation (there is plastic on the outside). The insulation is about half way up the wall.Since it starting getting pretty cold, we are noticing condensation in the back right hand corner of the basement, but nowhere else (we've tried to check behind the insulation and don't see anything). I've been running a dehumidifier to keep the humidity around 40%. We see the condensation forming about half way up the wall in the corner which is above grade. I understand that this happens when a cold surface (the concrete) comes in contact with humid air. I just don't understand why we're only seeing it in a small area and why it's not happening all over the concrete in that corner. The corner isn't insulated...the insulation runs up to that point and then stops.
Is it possible that something's wrong with the concrete there, is this simply the coldest part of the basement? There are large windows in the room that have absolutely no condensation on them. I'm just trying to determine whether this is something I can go back to the builder about, or something we'll have to deal with going forward.
Thanks, Jamie