ROXUL CAVITYROCK® Exterior Cavity Wall Insulation

Continuous Insulation for Optimal Thermal Performance

ROXUL CAVITYROCK® are high-density semi-rigid board insulation products designed for exterior cavity wall and rainscreen applications. This board insulation combined with the COMFORTBATT® thermal batt insulation in the exterior wall stud cavity offers superior long-term thermal efficiency, fire resistance, moisture control, and acoustic performance.


This product is specifically designed for use in cavity wall and rainscreen applications.

Product variations:
CAVITYROCK® in thicknesses of up to 2 inches, delivers an R-value/inch of 4.2 and is mono-density.

CAVITYROCK® in thicknesses of 2.5 to 6 inches, delivers an R-value of 4.3/inch, and is dual-density. This unique insulation combines a high density outer layer and a more compliant, low density inner layer that are created simultaneously in our proprietary manufacturing process.


  • Non-combustible stone wool insulation with melting point of approximately 1177°C (2150°F)
  • Fire resistant due to its high melting temperature
  • Water and moisture resistant; does not absorb moisture to maintain insulating value
  • Chemically inert
  • Does not rot, promote mildew, fungi, or bacteria
  • CFC- and HCFC- free product and process
  • Made from Natural and Recycled materials
  • ROXUL can contribute to earning LEED® points