A3.1.2 Mass Wall Rated R-Value of Insulation
The rated R-value of insulation is for continuous insulation uninterrupted by framing other than 20 gage 1 in. metal clips spaced no closer than 24 in. on center horizontally and 16 in. on center vertically.
Where other framing, including metal and wood studs, is used, compliance shall be based on the maximum assembly U-factor.