Back9.25.4.2.(5)

ATTRIBUTION:

Functional Statement:

F63

To limit moisture condensation.

F80

To resist deterioration resulting from expected service conditions.

Objective:

OS2.3

 

APPLICATION:

Membrane-type vapour barriers, other than polyethylene, in thermally insulated wall, ceiling and floor assemblies separating heated space from unheated space, exterior air or soil, in buildings to which Part 9 applies [see Sentence 1.3.3.3.(1) of Division A for application of Part 9].

INTENT:

To limit the probability that the performance of membrane-type vapour barriers, other than polyethylene, will fall significantly below expectations with respect to:
  • pliability,
  • tensile strength,
  • elongation under load, and
  • water vapour permeance.
This is to limit the probability of uncontrolled water vapour diffusion into insulated assemblies, which could lead to condensation, which could lead to deterioration, which could lead to compromised structural integrity of assemblies acting as environmental separators, which could lead to harm to persons.

ATTRIBUTION:

Functional Statement:

F63

To limit moisture condensation.

F80

To resist deterioration resulting from expected service conditions.

Objective:

OH1.1, OH1.2

 

APPLICATION:

Membrane-type vapour barriers, other than polyethylene, in thermally insulated wall, ceiling and floor assemblies separating heated space from unheated space, exterior air or soil, in buildings to which Part 9 applies [see Sentence 1.3.3.3.(1) of Division A for application of Part 9].

INTENT:

To limit the probability that the performance of membrane-type vapour barriers, other than polyethylene, will fall significantly below expectations with respect to:
  • pliability,
  • tensile strength,
  • elongation under load, and
  • water vapour permeance.
This is to limit the probability of uncontrolled water vapour diffusion into insulated assemblies, which could lead to:
  • condensation, 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 or 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 assemblies acting as 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.