131 - Two Q's: Isn't ZIP-R backwards? Shouldn't we rainscreen roofs as well as walls?

Two great questions on which the boys pontificate in fineform. Yes, ZIP-R is "backwards" (rigid insulation interior tostructural sheathing) but that does not mean that it doesn't work; itdoes, just differently. So why don't we typically rain screen roofcladdings? The short answer is it always costs more, regardless of thetype of roof cladding. But you know the saying: vent until youcan't...NOTE: - An Apology: Pete keeps saying "vinyl siding" when he means"vinyl wallpaper" in terms of what many older homes see as newly addedcovering over failed/failing plaster... Oh, and we can endlesslyapologize for Steve's parting "jokes"...PETE'S RESOURCES:- "Calculating minimum thickness of rigid foam sheathing"NOTE: Martin Holladay has more than one seminal GBA blog on the topicof adding continuous exterior rigid insulation to meet code--and evenbetter--for greater energy efficiency and maintained moisturemanagement.- "Avoiding Wet Roofs:"https://www.jlconline.com/how-to/insulation/avoiding-wet-roofs_o &https://www.jlconline.com/how-to/insulation/avoiding-wet-roofs-part-ii_o