Rigid Insulation Retrofit and Vapor Barriers

Helpful? 0

Rigid Insulation Retrofit and Vapor Barriers

I've spent hours researching my new wall detail and I'm down to one question, should I tape the 2" XPS Rigid Foam or not.


I am in Rochester NY (Climate Zone 5)

I have an existing home where I am taking the exterior down to the studs. I'm adding 1/2" OSB to the exterior (none now), 2" of XPS Rigid, Housewrap, 1x4 strapping and then a mix of cement siding and vinyl. The existing walls are 2x4 with R-11 Kraft Faced.

Should I tape the seams of the Rigid to create a secondary solid drainage plan? My only concern is that this will not allow the wall to dry to the outside at all (I know 2" of XPS is not very permeable, but I figured some vapor could escape through the untapped seams). I'm concerned about the drying as I'm planning on the wall to dry to the the inside but the existing batt insulation is kraft faced and this may limit the drying potential?

On a side note, this site has some great information. Thanks in Advance.

Asked by Matt Convery
Posted Sun, 12/09/2012 - 12:25