Yet Another Basement Wall Question

Man, are there are lot of different opinions about the absolute right or absolute wrong way to finish exterior basement walls. I know that everything depends on climate and existing conditions, so everyone's opinion is probably valid for at least one home out there.

My hope is that I can describe my situation and see what folks think my best approach should be.

Climate: Washington DC area - mid 90's and high humidity much of the summer, 30's and 40's much of the winter with occasional cold snaps in the teens or single digits. Perfect weather during the spring and fall.

Exterior conditions: Grade level ranges from 5' above basement floor to ~7'. Known groundwater issues, mitigated with a full perimeter interior french drain and sump pump about 18 months ago. Basement has been very dry since, with the exception of one crack in the wall that leaks maybe one drop of water per hour during very heavy rains. The sump pump definitely runs during rain storms and sometimes for a day or two afterward (very intermittently).

Existing wall construction: Built in 1938. Concrete block with a few sections of brick (I think for extra support in specific areas). House is block with brick veneer. Some parts of the interior basement walls have what looks like DryLok, but it could just be flat white paint. Some areas were previously finished in the 60's with pine paneling and have an off-white paint that does not feel like DryLok. These areas have since been painted with latex paint for aesthetic reasons. The entire perimeter has an 8" vinyl "baseboard" installed with the french drain and designed both to let any wall moisture drip down into the drain system, and to keep the backfilled hydraulic mortar from filling up the holes they drilled in the base of each vertical channel in the block walls.

For half of the year, the inside of the basement is the warm side. When it's hot out, the sections of wall above grade switch to being warm on the outside.

Even without insulation or registers, the basement is very comfortable year round. The HVAC and ductwork is likely responsible, except on days when no climate control is necessary and the earth is doing all the work.

Whew...I think that's all. Now, some things I've been thinking:

The french drain contractor said that I could line the walls with plastic and tuck it behind the vinyl "baseboard;" however, I'm hesitant to create such a nice place for mold to thrive.

The basement is small, so I'd like to avoid dedicating 4+" to wall construction. The previous pine paneling hung from furring strips that I have since removed. I was thinking about using 2x3s or 2x4s turned sideways on 2x2 pressure treated sole plates. The plates (regardless of the size I choose) would be adhered to the floor with Liquid Nails to avoid giving hydrostatic pressure a few dozen places to relieve itself onto my floor. While some have said you should avoid letting wood studs touch exterior walls, there seems to be more people advising not to leave a gap.

I have read about gluing 2" closed cell foam with taped seams to the wall to act as a vapor retarder and insulator. Supposedly, the foam breathes enough to dry itself out, and is thus not a barrier. The tape is to avoid heat transfer, not moisture movement. I have also read about people gluing drywall directly to the foam and calling it a day. This is a very attractive idea, if it works. I'll just use mollies for my wall hangings. I've considered putting the 2" foam between the aforementioned 2x3s or 2x4s, but this might be useless unless I seal it to the studs really well. In either of these situations, I'd have to cut channels in the foam for the electrical, and the boxes might penetrate all the way to the block wall.

Finally, in addition to requesting your general opinions, I have a question: If the agreed-upon solution is to use a vapor barrier or retarder on the inside of the wall, is it ok to penetrate it with electrical boxes, or should I force the box in place, pushing membrane a couple inches into the wall.

Many thanks to anyone who takes the time to read this and offer a possible solution!

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lilfos
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