We decided to get rid of the carpet in our basement in an effort to get rid of some mold and see if our allergies improved as a family. Well, the carpet and padding are gone and we’re working on a couple areas of the lower wall around the room.

In the process of scraping up the tack strip (which had like a tube of liquid nails per wall!) my scraper slipped in a couple spots, broke the drywall, went through the old paneling, and slipped right into the sill plate right up to the handle! The dilemma is… How much of this would we need to pull out? The room has a dropped ceiling and we really didn’t want to get into pulling all THAT down because that would mean more insulation… You know how all that goes. I’m HOPING we can get back to solid sill plate, add some sister studs, remove rotten parts below, add a header, then piece in studs below the header. Any other suggestions?

If we have to take the ceiling down it’s old and I’m sure it won’t go back up… Meaning buying all new tile. The insulation above isn’t installed properly (whoever insulated had NO idea the the ‘tabs’ were supposed to overlap the joist, they thought you shoved the insulation in further and stapled), and there are extra wires across the ceiling which we’d have to deal with. Yeah, I know we should do this anyway, we just didn’t want to do it NOW. That’s why the plan was to paint the floor for now until we can ‘do it the Holmes way’.

Two problems come to mind.
1) I assume concrete floors. If they were not installed properly you may have moisture coming through the floor itself. That would require rebuilding the floor. You would have to core drill to see what the problem is.
2) If the sill plate is damaged, you have to open up the wall to see how far the damage goes. It may go part way up your wall. However much sill plate and wall studding and drywall is damaged should be replaced. The sill plate and studding should be replaced with vapor barrier wrapped lumber to prevent future damage. Such lumber has to be properly installed to keep nails from leading moisture into the wood.

I would cut the wallboard at four feet. If you don’t have to go above that height, you can replace the wallboard horizontally, saving the upper wall and ceiling. In addition, when you open up the wall, you may find problems with the plumbing or electrical.

We are talking about concrete floors and masonry walls.
We have three potential sources… 1) there was a poorly installed shower in the adjacent bathroom that was removed and that area had mold as well. This wall would have been ‘path of least resistance had there been a large overflow from that shower, and 2) we did see water in the wall when we got 3 inches of rain in one hour and when the downspout came off our gutter in the back of the house during a heavy rain storm, and 3) the kitchen sink and dishwasher sit right over the worst of the problem.

The shower is gone, the downspout solidly extended further, and well there’s not much I can do about 3 inches of rain in an hour, but that doesn’t happen frequently. The plumbing to the kitchen sink was recently replaced due to repeated pinhole leaks in other areas, and the eventual kitchen remodel plan is to move the sink anyway.

There does not appear to be any issues with the floor (will tape the plastic to the floor tonight and confirm that). I’m not familiar with barrier wrapped studding. But since writing this we’ve decided to bite the bullet and tear out the entire wall, using treated wood for the sill, adding XPS insulation adhered to the wall, and rebuilding the entire wall and any adjacent areas that are mold infected, while sealing all air gaps at the top of the masonry.

Plumbing is overhead, vents and drains are visible above as well. There is electrical and I’m assuming we will replace the wiring between those outlets at a minimum (and add my third one while we’re at it).

It’s a lot of work but you can replace the bottom plate without removing the whole wall. We did some of this after floods locally after flooding. Cut away the drywall on both sides of the wall if possible. Inspect the bottom plate and the bottom ends of the studs for rot. The wall must be supported while you work. You can build a support wall on one or both sides holding up the ceiling joists. Or if that isn’t possible screw a ledger into each stud on both sides of the wall if possible a 2×4 will work and then put angled supports from the ledger to the floor to support the wall. the bottom plate can be cut out and the bottom of the studs too if necessary and replaced. Remove the supports and replace the drywall.