(1)
Except as provided in Sentences (2) and (3), air barrier assemblies not in contact with the ground shall
(a)
conform with CAN/ULC-S742, “Standard for Air Barrier Assemblies – Specification,” and
(b)
meet the selected Performance Class of Table 5.4.1.1. (See Note A-5.4.1.2.(1))
(2)
Air barrier assemblies not evaluated in accordance with CAN/ULC-S742, “Standard for Air Barrier Assemblies – Specification,” shall be designed and constructed
(a)
to meet or exceed the selected Performance Class of Table 5.4.1.1., and
(b)
with at least one air barrier material intended to provide the primary resistance to air leakage that meets the requirements of CAN/ULC-S741, “Standard for Air Barrier Materials – Specification.” (See Note A-5.4.1.2.(2))
(3)
Air barrier assemblies covered in Subsections 5.9.2., 5.9.3. and 5.9.4. shall meet the air barrier performance criteria defined in those Subsections.
(4)
Below- grade air barrier assemblies in contact with the ground shall minimize the ingress of airborne radon and other soil gases. (See Note A-5.4.1.2.(4))