re: basement foam insulation question

[hollow door]

Hello,
i have a concrete block foundation wall. XPS was foamed in place with 2x3 lumber in front.
Climate is 4000 Celsius heating degree days (7200 Fahrenheit). (Toronto, cold climate, warm summers, moderate rain)

I intend on soundproofing one room as best as possible. According to this detail (figure 14) in buildingscience.com, unfaced batts can be placed in front of the XPS foam. I see no PE layer. I was thinking about using 2" of Roxul AFB similar to that detail. The home is old, with damproofing on the exterior block but no drainage mat.

http://www.buildingscience.com/docum...lation-systems

Have any of you ever built this detail or seen it work safely (placing no vapour control layer in front of batts in a similar cold climate)
thanks

[BadgerBoiler MN]

Re: basement foam insulation question

Yes.

I used fiberglass over Thermax in my 1921 poured foundation and covered all with drywall. The insulation will not dry to the outside in most cold climates and if you are finishing a basement one assumes you will condition it.

For three months in the summer I run a dehumidifier to keep rH below 65%. Otherwise all is perfect with the radiated floor.

We radiate many basements with rubble foundations here in Minneapolis and spray foam most of them with stud wall and fiberglass with perfect results.

With non-hydroscopic mineral wool, a vapor barrier would truly be wasted.