Protection of structural wood elements that have been treated with borates, where these elements are:

• in termite-prone localities, where the clearance between structural wood elements and the ground is less than 450 mm or not all sides of supporting elements are visible,
• in termite-prone localities, where a barrier is not installed through finish materials on insulated foundations or not all sides of the finished supporting assembly are visible,
• in all localities, where the vertical clearance between structural wood elements and the ground is less than 150 mm,
• in all localities, where
  • the wood elements are not protected from exposure to precipitation,
  • the configuration is conducive to moisture accumulation, and
  • the moisture index is greater than 1.00, and
• in all localities, where structural wood elements are used in retaining walls and cribbing, and where
  • the retaining wall or cribbing supports ground critical to the stability of building foundations, or
  • the retaining wall or cribbing is greater than 1.2 m in height.

This applies to buildings to which Part 9 applies [see Sentence 1.3.3.3.(1) of Division A for application of Part 9].

To limit the probability that performance, with respect to the protection of structural wood elements from termite infestation or decay, will fall significantly below expectations. Where structural wood elements support or are used in an environmental separator, this is to limit the probability of compromised performance of the building envelope, which could lead to:

• condensation,
• precipitation ingress, or
• compromised thermal performance of components intended to provide resistance to heat transfer.

This is to limit the probability of:

• an inadequate control of indoor air and surface temperatures, drafts, relative humidity, or water accumulation,
• the generation of pollutants from biological growth or from materials that become unstable upon wetting, or
• deterioration, which could lead to further compromised integrity of environmental 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.

To limit the application of the standard to situations where the limited protection provided by borates will be adequate.