OK, now I understand. I would use only pressure treated or metal structural support and styrofoam for insulation. Then, green wallboard (moisture resistant). I would install it with screws, but not tape the seams. Cover the seams with a nice piece of wood trim which could easiy be removed accessing the drywall sections. Would only be necessary to locate the screws for the center studs for the section when removing one. As for an entirely removable section, I believe it would be necessary to attach the drywall to plywood or another surface. My concern, based on the conditions you describe, is that the plywood would warp and ruin the wall. Another thought - install a flush door (either hinged or a door panel) where the problem areas need inspection. Hope this helps a bit.

thanks all. --probably thought I'd gone away, taking so long to answer. It just seems one "challenge" follows another. The time goes by and you try to hold things together or repair things including your body and sometimes, things just keep coming. Hopefully, I'm forgive for being long time in answering. It's been in & out of docs. for me and tonight, wife goes to hospital. I managed to get a small, very small, strip piece of the paneling off, intact. I used a blow dryer to heat it. The adhesive cement is very, very strong. the blow dryer took a long time to heat the wood--I thought it was going to scorch , before the paneling came loose, but I finally got it. That 4"x4' section took over an hour of work! There does seem to be though a magic temperature, if I can get up to it, the adhesive softens enough to let me hammer a putty knife between it and the wood, other wise--no go. the putty knife won't cut it and the piano wire I tried to use, broke. I hoped that was the piece that would give me access to what I needed to work on, but no. I'll have to remove at least, maybe two, of the full 4x8 sheets. If I destroy this Walnut, there will be no way to replace it. And I do not want to have to figure out some other way to refinish the basement--I guess I could glue sheet rock to the walls, if I glue enough shims in first. I just hope I can get the panels down. You'd think that 30+ year old glue after being so old and going through freezes and thaws would be brittle and give way, but it sure doesn't. Probably the easiest way is to pry the furring strips from the walls and try to put them back up? Because of the unevenness of the concrete walls the strips are glued on both horizontal and vertical. And to get them off, I'll have to take down the entire wall! -- ouch! Is that the only way? I did such a great job putting this stuff up, I can't even see the finishing nails I used to make certain the panels stayed attached to the strips while the glue set. Then of course, I dabbed a bit of paint, the same color of the dark, vertical seams they are in, on the nail head. they are virtually invisible. To find them, I hope a magnet will work. If I pull off the furring strips, they won't be a problem. If I try to take off the paneling, I'm not certain if I have enough room to drive them through the panels before they hit the concrete. What a job. In removing the one little piece of paneling, I learned that I'm going to have to pull an entire corner of the ceiling tile down, as well. It just gets worse and worse...or maybe I should look at it as an exciting challenge? Let's see if I can do it? --yeah, right :( Instead of using a hair-dryer to try to heat the wood, what about trying an electric iron? Think I could do that without scorching the paneling? If so, how high of heat would you set it to and what would be good to put between the bottom of the hot iron and the paneling? --I don't think laying an iron, directly on the walnut, would be very good for it. Or should I just give up and try to separate the furring strips from the wall, leaving the paneling attached. --What a nightmare it was putting those up--absolutely nothing was plumb, level. It took hours and hours to get them level and plumb. Maybe there's an expert way to get these down--it'll take at least 4 people to take a wall all in one piece, especially to not cause damage to any of the panels. Then, how do I get it back up? Is it time to throw the walnut away and put up sheet rock? Bob

I have the same wall construction in my 1940 house - plaster over rock lathe (which looks like sheetrock). Careful work with the oscillating tool will generate some dust, but if you are patient you can get nice clean cuts through all the layers. I have plumbing access panels in three places, and have not noticed any increase in plumbing noise. If you do hear noise, you could stuff batt insulation in through the panel opening, and just pull it out when you need access. Take a look at the metal access panels available from HD and Lowes. The biggest one that will fit easily is about 14" x 14", so it is designed to fit between standard spaced studs. You can cut out the opening, slip in the panel, and put screws through the flange on each side into the studs. Its a fast install once you get the opening cut. I painted mine the same color as the wall, so it blends in nicely. They also make larger metal access panels, but you would have to frame an opening for them. I did do that in my basement where the gas meter is hidden behind a much larger panel. Bruce

You still need a GC. A 5-20K job is not nearly as small a job as you think. You have electrical in the walls. Maybe HVAC. Maybe plumbing vents or pipes.. Flooring gaps that have to be filled, or all new floors. Drywall work. Painting. Moldings. And that’s in addition to creating the point load supports that support the header. Because something has to support your ceiling drywall, even if the wall doesn’t support the roof.