Intent 1:
To limit the probability that concrete blocks will
be unable to resist expected structural or environmental loads. 
This is to limit the probability of: 
- excessive moisture transfer through masonry units, or
- deformation or cracking, which could lead to: - where masonry units support or are part of an environmental
separator, the excessive deformation, displacement or failure of required
environmental separation elements, or
- where masonry is used in chimneys and fireplaces, compromised
integrity of chimneys or fireplaces.
 
This is to limit the probability of: 
- condensation, 
- precipitation ingress,
- moisture ingress,
- excessive heat transfer,
- pollutant ingress, or 
- compromised thermal performance of components intended
to resist heat transfer.
This is to limit the probability of: 
- an inadequate control of temperatures in interior spaces,
drafts, relative humidity or water accumulation,
- the generation of pollutants from biological growth
or from materials that become unstable on wetting, 
- deterioration, which could lead to further compromised
integrity of environmental separators, or
- where masonry is used in chimneys and fireplaces, the
leakage of combustion products. 
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.