20th April 2024

Cavity Wall Insulation

Most common type of External Wall Insulation, also referred as sandwich wall insulation. Where Insulation is sandwiched between two substrates of construction like Concrete or Block wall, Precast concrete panels or combination. Cavity is generally referred to a void formed between these substrates and to avoid thermal transfer between the substrates the cavity is filled with material having very low thermal conductivity so is called Cavity wall Insulation.

SRW offers wide range of Rigid and Semi Rigid Rockwool Insulation Boards suitable to use with in the cavity manufactured in accordance with ASTM C 612 & BS EN 13162 & various other international Standards. Product can be selected in a combination of thickness and density suitable to match thermal performance desired.

SRW Cavity Board can be supplied un-faced or Factory Applied Vapor Barrier (FSK) or Breathable membrane in accordance with Project requirements.

SRW Rockwool Cavity Board Benefits

  • Water Repellant Grade
  • Excellent Thermal Efficiency
  • Non-Combustible
  • Euroclass Fire Classification – “A1”
  • “zero” Flame Spread Index
  • “zero” smoke Developed Index
  • UL Greenguard Certified
  • FM Approved
  • Fungi / mold Resistance
  • No Capillary action
  • Acoustically Absorbent




Compliance Standard

Thermal Conductivity


0.033 -0.034

ASTM C 177 / ASTM C 518



70 - 100

ASTM C 303

Compressive Strength


2.5 - 20

ASTM C 165

Surface Burning Characteristics

•Flame Spread Index
•Smoke Developed Index



ASTM E 84 / UL 723

Moisture Absorption



ASTM C 1104

Water Absorption



BS EN 1609

* Lower or Higher Densities can be provided in case desired