The 1.5-inch panel is a composite material consisting of three primary layers:
: A 1-inch thick layer of polyisocyanurate (polyiso) foam bonded to the back of the OSB.
: In Climate Zone 5, the R-6.6 provided by the 1.5-inch panel is sufficient to keep the sheathing boundary above the dew point, preventing internal condensation when using fiber insulation in the stud cavity. 4. Application and Code Compliance 1.5.zip
: The overlay typically provides a permeance level of 12–16 perms , allowing the panels to "breathe" and dry out.
The 1.5-inch variant is often the minimum thickness required in the ZIP-R product line to satisfy energy codes in colder climates. However, designers must account for specific regional requirements: Roxul Comfortboard - disadvantages? - GreenBuildingAdvisor Application and Code Compliance : The overlay typically
The primary benefit of the 1.5-inch ZIP-R system is the elimination of . In traditional framing, wood studs act as thermal bridges, conducting heat out of the building. The 1.5-inch ZIP-R provides continuous insulation that can cut wall heat loss by 20–30% compared to cavity-only insulation. Other advantages include:
, significantly lower than standard OSB and housewrap combinations ( 3. Advantages in Construction - GreenBuildingAdvisor The primary benefit of the 1
: When properly taped, ZIP walls can achieve air change rates of