Hello!

I’ve got quite a complicated situation in my basement that I’ve been struggling with for years. The time has come to get everything finished up, so I need to make some critical decisions. For reference, I live in Atlanta, GA.

My home is a 1950’s ranch that was on a huge crawlspace. 60% of the crawl space had been “finished” and the other 40% was dirt floor with shower-pan liner laid all over it but not sealed (no idea). The crawlspace vents had been sealed, but no fresh air was introduced. As you can imagine, this created huge issues down there I had to remedy first.

I sealed the 40mil shower-pan liner and had a radon fan installed to vent all that foul air outside. This helped dramatically. I also installed an ERV and a Santa Fe Compact 2 Dehumidifier in the crawl space portion to keep air fresh and clean and dry. There are french drains and a sump in the room that pumps outside, and this is where all my HVAC is located as well as my hot water heater.

At this point, there is 0 insulation on the walls of the basement or crawlspace, although the crawl has the 40mil poly going up the walls to a couple inches from the top of the foundation.

The previous owners had tried to finish half the crawlspace into 2 basement rooms for one of the sons, but did a horrible job of it. The floors are poured concrete and no wood touches the sealed up dirt, but furring strips were nailed to most of the wall, even the portion that was sub-grade, and poly was placed over the furring strips and beneath the drywall.

As you can imagine, this created some mold issues, which I’ve had re-mediated, and also fixed the exterior water issues that caused them (downspouts terminating straight at the foundation).

There were actually only 2 small spots that had water issues, as out of the 4 walls that created the “finished” portion of the basement. only 2 had portions that were sub-grade, and there were a small percentage of the wall near the bottom.

The only area with any real issue we complete gutted, covered the exterior area above it with concrete, and plan to build a framed wall away from any concrete to give any weeping the ability to vent into the dehumidified crawl-space. We’ll also thoroseal it, so that should be completely fixed and a non-issue.

The 4th wall is along the backside of the house, has a poured driveway outside it all the way to the brick, and has an addition over that, so it sees no water. This, surprisingly, of all the walls, is the only one with a proper stud-wall with spacing off the concrete blocks. This will be insulated first with closed-cell foam.

We had a flood cut done when we thought there was a mold problem, so the drywall and poly on the bottom 4ft is gone.

The ceiling is a drop ceiling with the grid in-tact still, and I’d love to keep it that way.

As of now, we don’t want to tie the basement into our primary heat pump, and would heat/cool it with window units and portable heaters, or a mini-split heat pump if we start using it a lot.

The ceiling above the finished part will still connect to the ERV’d Dehumidified portion of the sealed crawl space.

We primarily want to finish the basement to have some extra space for storage, allow overflow for events like watching football games. It would not be used on a daily, or regular, basis, right now.

I’ll easily be able to insulate the one wall we completely gutted, and I can spray foam 70% of the above-grade wall on the back. The real issue is the 3’rd wall (mostly above grade) and the area where the stairs come down from the house. This has lots of complicated drywall on the above-grade wall in the back.

Here are the big questions:

1) Is it worth ripping down the rest of the drywall, insulating the walls with closed cell foam (board or spray) and creating stud walls where the furring strips were on a non-issue wall? This seems like it would be a great deal of cost just to get a few inches of foam back there and if there weren’t moisture issues from the 20 years it was under that horrible setup, I don’t expect them now.

2) Would ripping everything down, installing foam board and putting everything back up be worth the thousands of dollars and many man-hours extra it would cost in comfort and energy savings?

3) Am i exposing myself to any sort of crazy issues by not refinishing without insulating? There were none before, and I will not be using poly, like there was, just putting drywall back up and finishing it back out. Will there be any problems if 70% of these exteriors walls are insulted in some way or another but the remaining 30% are not?

I want to do this right, but only to the point that I will actually see ROI on it. I would never dream of not insulating a basement done from scratch, but to rip much of it down to put insulation back up seems it may be excessive.