New interior wall on or "under" floating floor?

[McZ]

I am in the process of renovating the upstairs of our 1.5-story house. I am planning to soundproof the floor and build a new room. But I'm unsure of the order in which to do it.

The soundproofing of the floor will be (as I found in other threads)

• Existing 22mm chipboard floor
• Soundproofing e.g. Paroc SSB 2t
• New floating 12mm chipboard floor (or 16mm?)

But should I install my new interior wall before I build the soundproofing of the floor, or after?

How will the wall handle movement if I install it on the floating floor?
What should be done with doors if the wall is installed before the floating floor?

Existing upstairs


New upstairs

 

[huggan]

If the sound between rooms on the upper floor is important, you should do the walls first, alternatively just the chipboard and then the interior walls.

 

[McZ]

Yes, I think sound is quite important, so it will have to be the wall first.

How do you do it at the door? A fixed rule with the same height as the floating floor, but narrower than the threshold so that the floating floor goes under the threshold a bit?

 

[huggan]

Yes, that is a solution, or do you let the spånet go in there but with a 10 mm gap between the different spånskivorna.