9.23.16.4.(2)

Intent 1:

To limit the probability of inadequate clearance, which could lead to an inability to accommodate dimensional changes due to changes in moisture content, which could lead to jamming of sheet edges, which could lead to buckling, which could lead to damage to roofing.

Where wood-frame construction supports or is part of an environmental separator, this is to limit the probability of the displacement or failure of required environmental separation elements, which could lead to:

• precipitation ingress, or
• compromised thermal performance of components intended to resist heat transfer.

This is to limit the probability of:

• an inadequate control of temperatures of interior spaces or water accumulation,
• the generation of pollutants from biological growth or from materials that become unstable on wetting, or
• deterioration, which could lead to further compromised integrity of environmental separators.

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.