I also posted this in the basement forum-

We were going to install vinyl plank flooring in our rec room basement but after pulling up all the carpeting we found a large sometimes raised crack in the concrete floor running from the south wall to the east wall, about 15-20ft long. One end of this crack I had put some leveling compound on about 5 months ago while the carpeting was pulled back for another small project. I see now it has moved horizontal about 1/16 inch since.

It's worse in a 2-3ft length where the crack is about 3/16 to 1/4" wide and a vertical rise of maybe 3/16". But for most of the crack's length, the rise and spread aren't too bad - 1/8" or less. We have not had water come up from this large crack and have lived here over 20 years. We have had water come in through the wall or wall/floor joint.

The house is a early 70's split level on a sloping yard. West end of the rec room floor is actually above grade (that foundation wall piered), and 2 sides (north and east) have a sub floor drain with sump pump. East end about 3ft below grade.

So I guess my question is could the crack be stabilized with epoxy or ? and should the idea of the vinyl plank flooring be scrapped even if we smooth and level the cracks? We are considering going with carpet again because of the floor movement. Or can the vinyl plank flooring take a little floor movement without creating gaps? Would putting sheet plastic under the vinyl plank flooring help it slide? Or what would be the best flooring with a moving floor?

Thanks in advance.

Ken