Exterior insulation retrofit suggestions?
I have purchased a house in Vermont and it needs new siding. This is the perfect opportunity to add more insulation!
The current wall construction from the inside to out is: 1/2″ gypsum, 4 or maybe 6 mil poly, 2×4 with R-11 fiberglass batts 16″ OC, 1/2″ plywood sheathing, some sort of building wrap, and vertical wood siding.
The reading I’ve done on GBA has made me very nervous about adding polyiso to the exterior of the wall, due to the presence of the poly on the interior. Can anyone suggest an alternative insulation retrofit to the exterior of the house? If it makes any difference I’m looking at cedar shingles for new siding, but am also considering Hardie Board.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part