9.18.6.2.(4)

Intent 1:

To limit the probability of discontinuity of the air barrier system at penetrations through the ground cover, which could lead to the ingress of moisture that is not under hydrostatic pressure from the ground.

This is to limit the probability of:

• an inadequate control of relative humidity,
• the generation of pollutants from biological growth or from materials that become unstable on wetting, or
• deterioration, which could lead to compromised integrity of environmental separators or of elements protected by the separators.

This is to limit the probability of:

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

This is to limit the probability of harm to persons.

Intent 2:

To limit the probability of discontinuity of the air barrier system at penetrations through the ground cover, which could lead to the infiltration of soil gas, which could lead to negative effects on the air quality of indoor spaces, which could lead to harm to persons.