Zip insulated panels PLUS rigid insulation for warm sheathing?
architect_sean
| Posted in Green Building Techniques on
I am a fan of two things: energy conservation and warm sheathing. I see some terrific labor saving advantages to the INSULATED Zip sheathing system BUT it leaves the sheathing out in the cold where it doesn’t tryout as well. Has anyone ever considered using the insulated zip system PLUS added rigid insulation on the outside of the sheathing to keep the sheathing warm? How about insulated zip system with and EIFS system on the outside?
If you have a favorite wall assembly that keeps the sheathing warm please share. I am an architect interested in hearing how you approach the process.
Thanks – Sean
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
Hi Sean.
I can't see why you would want to use ZIP R-sheathing and additional exterior insulation. First, I believe that in order to keep the sheathing warm, you'd need the same R-value, if not a higher R-value of exterior insulation as you would if you hadn't used the ZIP R. Second, the OSB layer of the ZIP sheathing will have limited drying potential in both directions, unless you chose a vapor-open exterior insulation like mineral wool or wood fiber.
This topic is discussed in this article: Working with ZIP R-sheathing
If you want the sheathing to stay warm, why not just use structural plywood or OSB sheathing (or uninsulated ZIP) and an adequate R-value of exterior continuous insulation for your climate?
More on getting this assembly right here: Walls that Work
Thanks Brian. Your logic seems sound. Sometimes just putting the question out there raises some new thinking. You were helpful. Thanks for the links!