Fastening of lumber, wood shingles, shakes, fibre-cement shingles, planks and sheets, plywood, oriented strandboard, waferboard, hardboard, vinyl, aluminum and steel, including related trim and soffits, asphalt shingles or stucco installed as cladding on wood-frame walls exposed to precipitation, on buildings to which Part 9 applies [see Sentence 1.3.3.3.(1) of Division A for application of Part 9].

Exceptions: 

To limit the probability of fastening cladding to an inappropriate substrate.

This is to limit the probability of:

• an inadequate resistance to expected gravity loads and lateral wind loads, or
• where panel-type siding is installed as bracing to satisfy Subclause 9.23.10.2.(2)(b)(i), an inadequate resistance to expected lateral loads, which could lead to racking of exterior walls.

This is to limit the probability of:

• the displacement of cladding, trim and flashing, the opening of joints or the failure of caulking, or
• where panel-type siding is installed as bracing to satisfy Subclause 9.23.10.2.(2)(b)(i), the displacement or failure of other required environmental separation elements.

This is to limit the probability of:

• precipitation or meltwater ingress, or
• compromised thermal performance of components intended to provide resistance to heat transfer.

This is to limit the probability of:

• an inadequate control of the temperature of interior spaces or relative humidity,
• the generation of pollutants from biological growth or from materials that become unstable on wetting,
• deterioration, which could lead to compromised integrity of exterior walls or elements protected by exterior walls, or
• water accumulation in interior spaces.

This is to limit the probability of:

• negative effects on the air quality of indoor spaces,
• the inadequate thermal comfort of persons, and
• contact with moisture.

This is to limit the probability of harm to persons.