Carpet desgin beedroom problem
Is this a really dry basement?
The reason I ask is, what I have done is lay a 6 mil. plastic vaper barrier then foam panels the thickness of that step up then went over that with 3/4 T & G Advantec. then Tap Coned all that to the floor.
It acts like a thermal break and does not move at all.
Why are you using a 4 X 4 as a bottom plate? Need to at least put some sill seal under it or it going to rot, and cut the one sitting on that step so it's all even across the top. Would have been much better to have made it all one piece.
How did you even attach it to the floor?