Rainscreen Cladding with DOW THERMAX Wall System & Metal Stud Backup






 Interior Finish (vapor permeable)--
 Interior Gypsum Board (Type X) -
 Metal Stud (18 GA. Min. @16” O.C.)- -
 Stud Cavity Insulation (Optional)*Dow2" Styrofoam SPF CM-2045
 Continuous Insulation*Dow2" Thermax XArmor
 FlashingDowLiquidArmor CM 
 Cladding Attachment SystemKnight WallCI System
 Rainscreen Cladding*-NFPA 285 Compliant

* Product recommendations are based on Type I-IV construction requiring NFPA 285 assembly acceptance criteria compliance per IBC 2015 Sections 1403.5 & 2603.5.

Assembly Performance:

(proposed clear wall U-Factors are approximately 2% | 25% better than code and have 91% | 80% thermal effectiveness)


Code Minimum
(IECC 2015 - Metal Framed)


Design R-Value: aR-13 + R-7.5ciR-13ci  |  R-12.8 + R-13ci
Total R-Value:N/AR-17.09  |  R-29.86
Effective R-Value:cN/AR-15.56  |  R-23.88
Design U-Factor: a, bU-0.064U-0.063  |  U-0.048
Effective U-Factor: cN/AU-0.064  |  U-0.042
Assembly Air Permeability0.04 cfm/ft2 @75Pa0.01 cfm/ft2 @75Pa

Clear wall meets energy code thermal requirements without stud cavity insulation.

b Clear wall U-Factor is based on the stud size & spacing noted above and is calculated per IECC 2015 & ASHRAE 90.1-2013 Appendix A.

Clear wall effective thermal performance is based on the stud size & spacing noted above, manufacturer literature and industry studies on the thermal performance of facades.


Click here to download a complete copy of this opaque wall Basis of Design package