Insulating basement walls of inside unit town house
I currently live in a new 4 unit townhome. I am an inside unit with only 2 outside walls. The basement walls between the units are poured concrete approx 8 inches thick from what my brother was telling me. the units on either side and my basement are heated (conditioned). The outside walls are studded approx 2.5" from the concrete wall and then pink fiberglass insulation was installed as well as vapour barrier. The vapour barrier was only stapled up with no sealant on any of the studs or top/bottom plate.
I plan on installing drywall this spring, but would like to install some sound proofing on the inside walls and above the concrete where there is the drywall fire stop. I also plan on installing 2" rigid foam insulation on the rim joist.
The inside walls have been studded by my brother at 24" on centre at approx 2.5" from the concrete and then one stud wall is only about an 1.5" from the concrete. Can I just use Roxul sound insulation and then drywall or do I need a vapour barrier as well? I have been doing searching online and can't really find anything that answers my question clearly.
If it helps, I live in Spruce Grove, AB (Edmonton) Canada.