Intent 1:
To limit the probability of unprotected access openings,
which could lead to:
- where crawl spaces are unheated and access is from the
interior, moisture transfer from the interior, or
- where crawl spaces are heated or unheated and access
is from the exterior:
- the ingress of precipitation,
- an infestation of insects or vermin, 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, relative humidity or drafts,
- 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,
- the inadequate thermal comfort of persons, and
- contact with moisture.
This is to limit the probability of harm to persons.