9.20.2.1.(1)

Intent 1:

To limit the probability that performance, with respect to loadbearing capacity, water transfer and freeze-thaw resistance, will fall significantly below expectations, which could lead to an inability to resist expected gravity or lateral loads, as well as moisture or temperature loads.

This is to limit the probability of:

• where masonry construction is required to provide fire resistance, excessive deformation or cracking, which could lead to compromised fire resistance of the assembly, or
• for chimneys and fireplaces, excessive heat transfer, which could lead to the ignition of combustible building components.

This is to limit the probability of damage to the building.