Rigid foam insulation in stud bays
Got a question about putting XPS foam panels in stud bays (what a pain….).
Any worries about double VB between foam panels? Dow told me once to put building paper on the stud faces to stop moisture permeating from the wood to between the foam panels. But that’ll get in the way of foaming between the stud and the foam panels. Last time I did this I used 3″ foam panels, but there’s only one place in greater NYC AFAIK that carries these, everywhere else swears up and down they don’t exist. So it’s off to HD for 2″ and 1-1/2″ panels. Perhaps if I glue the panels together…..but what glue is good for XPS? PL100 definitely not, can’t find PL300 (of course) and polyurethane glue will expand and push the panels apart.
Replies
"Any worries about double VB between foam panels?"
No, since there is no void of any significance between the layers.
Also, if you are foaming around the edges, there is no place for moisture laden air to get in.
No need to glue the layers together, though you might need to brace them while the gun foam sets up. Gun foam tends to push the panels outwards as it expands.