• Insulation must be in contact with an air barrier.
  • A-9.25.2.3.3) For Thermal Insulation to be effective, it must not be short-circuited by convective airflow through or around the material.
  • Air spaces around insulation leads to convective airflow which greatly reduces the effectiveness of the insulation.
  • Thermal insulation must therefore be installed in full and continuous contact with the air barrier or another continuous component with low air permeance.

9.25.2.3.3) Except where the insulation provides the principle resistance to air leakage, thermal insulation shall be installed so that at least one face is in full and continuous contact with an element with low air permeance.