Back5.5.1.2.(1)

ATTRIBUTION:

Functional Statement:

F63

To limit moisture condensation.

Objective:

OH1.1, OH1.2

 

APPLICATION:

Properties and location of materials installed to provide resistance to vapour diffusion through building assemblies, and through interfaces between assemblies described in Sentence 5.1.2.1.(1) that are installed in buildings to which Part 5 applies [see Sentence 1.3.3.2.(1) of Division A for application of Part 5].
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].
This also applies to the design of vapour barriers in 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 is more susceptible to condensation [see Sentences 9.25.4.2.(2) and (3) for combinations of interior and exterior environmental conditions that create a higher risk for condensation].

INTENT:

To limit the probability of installing materials that are unable to adequately control vapour diffusion (except the diffusion of moisture from the ground) through environmental separators under expected environmental loads, which could lead to condensation.
This is to limit the probability of:
  • 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.
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.

ATTRIBUTION:

Functional Statement:

F63

To limit moisture condensation.

Objective:

OS2.3

 

APPLICATION:

Properties and location of materials installed to provide resistance to vapour diffusion through building assemblies, and through interfaces between assemblies described in Sentence 5.1.2.1.(1) that are installed in buildings to which Part 5 applies [see Sentence 1.3.3.2.(1) of Division A for application of Part 5].
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].
This also applies to the design of vapour barriers in 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 is more susceptible to condensation [see Sentences 9.25.4.2.(2) and (3) for combinations of interior and exterior environmental conditions that create a higher risk for condensation].

INTENT:

To limit the probability of installing materials that are unable to adequately control vapour diffusion (except diffusion of moisture from the ground) through environmental separators under expected environmental loads, which could lead to condensation, which could lead to 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.