1.5.zip May 2026

, significantly lower than standard OSB and housewrap combinations ( 3. Advantages in Construction

: A 1-inch thick layer of polyisocyanurate (polyiso) foam bonded to the back of the OSB. 1.5.zip

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 , significantly lower than standard OSB and housewrap

: 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 Application and Code Compliance : When properly taped,

: When properly taped, ZIP walls can achieve air change rates of

: The overlay typically provides a permeance level of 12–16 perms , allowing the panels to "breathe" and dry out.

: It combines multiple steps (sheathing, WRB, and exterior insulation) into a single installation, which can be faster and cheaper than applying separate layers.