Thoughts on adding rigid insulation over existing siding.
We have a historic house that is undergoing a deep energy retrofit with rigid insulation being applied to the outside and then strapping and new siding. The contractor has ripped off a few layers of asphalt siding and is now down to the original siding. He would like to keep it on and simply put the new rigid insulation over the siding. It seems this will create some nice air pockets which be good insulators, and be a cavity for drying if needed. Does anyone have experience doing this and any input on pros and cons versus taking that original siding off and going down to sheathing?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part