Planning the renovation of a 110 year-old cottage in Indianapolis. Looking to put 1" of rigid foam on the outside before re-siding with fiber cement lapboards, and 3.5" of wet spray cellulose inside. We do have wood sheathing, horizontally hung 1x boards, on the exterior of the wall studs.
Is the furring strip over the foam advisable because it will 1) allow air circulation behind the siding or 2) provide structural support when hanging siding? Or both?
Or, with the relatively narrow foam, is it not required?