APPLICATION:
This also applies to the position of low air and vapour
permeance materials within the
building assembly relative to the position of materials providing thermal resistance in the
assemblies of
buildings to which Part 9 applies [see
Sentence
1.3.3.3.(1) of Division A for application of Part 9], where
the
building assembly:
- incorporates low permeance materials that act as other than
cladding or that are installed on the warm side of the assembly, and
- is more susceptible to condensation [see Sentences 9.25.1.2.(4) and (5) for combinations of interior and exterior environmental conditions that create
a higher risk for condensation].
INTENT:
To limit the probability of the inadequate control of heat
transfer through environmental separators under expected environmental loads,
which could lead to condensation.
This is to limit the
probability of deterioration, which could lead to compromised structural integrity
of the separators or of elements supported or protected by the separators,
which could lead to structural failure, which could lead to harm to persons.