Robinhood, we can discuss our beauty issues here...glad to see you posting, sometimes I have problems here, but not all the time...Gloria

Any wood flooring over concrete in contact with the earth usually requires the services of an experienced professional to get it right the first time. Whether or not you're going to install plywood first (an obsolete method in my professional opinion), the concrete needs to be FLAT and you need to make it flat before starting the job. Wood manufacturers will state how flat that needs to be. And, you need to know how much moisture is coming through a slab before you do anything to it or apply any flooring to it.

Possible the foundation is settling or moving because of all the rain and its age. A crack could have developed right there which would either allow moisture in, or perhaps the concrete on one side of the crack is moving up or down relative to the other. You might want to have a professional look at it. Someone with foundation or structural experience.

AND.....the hits keep coming............ I have not seen any further activity in the house. I keep checking...but nothing. Holding my breath but hopeful. HOWEVER...today I decided to clean out my shed. It is an all wood 8x12 structure that I built myself in the corner of my backyard. It is built upon four 6x6 posts (embedded in concrete) and is four (to six) inches above the ground (suspended). I had a large hardwood tabletop and a big piece of butcher block countertop stored in there. As I was removing items I noticed a large blemish on the tabletop. I thought I might have scarred it with a bicycle that I'd had hanging next to it. Nope....termites. I pulled the tabletop (and butcher block) away from the wall and they were prettly well chewed up. I soaked them with bug killer (because I didn't want to unleash live insects into the wild) and hauled them to the curb. Then I noticed that tremites had chewed up the plywood inner wall of the shed. Mud tubes (might as well be..mud WALLS) were erected in the corner of the shed. One single mud tube went all the way to the ceiling. It had all been hidden by that giant tabletop. There was damage in one other area as well....and I could HEAR the termites munching away. The damage is pretty harsh but IS salvageable (and does not appear to be structural). I doused all the affected areas with Termiticide. The termites also munched on other pieces of scrap project wood I'd been storing in there. I trenched around the back and side of the shed and (in the back) found a LIVE cluster of termites and mud tubes centered around some decorative stones I'd placed around the base of the shed. This area is CONSTANTLY moist (due to rain and shade). I soaked the trench in termiticide (including the backfill) and will complete the treatment for the front and other side tomorrow. I am exhausted. If anyone else has gone through this...I feel your pain. The destruction of these little buggers is unreal. I am confident I can patch my shed up...but man....what a frustrating pest to deal with. Cheers.