Illustration Source: Summerhill

9.25.2.3. 7) Except as permitted in Sentence (8), insulation and vapour barrier shall be protected from mechanical damage by a covering such as gypsum board, plywood, particleboard, OSB, waferboard or hardboard.

8) In unfinished basements, the protection required in Sentence (7) need not be provided for mineral fibre insulation, provided it is covered with polyethylene vapour barrier of at least 0.15 mm in thickness.

(0.15 mm is 6 mil)