To limit the probability of the entrapment of moisture
inside closed building envelopes, which could lead to:
- excessive post-installation shrinkage and warping,
- wood decay, which could lead to a loss of lumber strength,
- the exposure of other materials that are moisture-sensitive
and susceptible to decay to high moisture levels and decay fungi.
This is to limit the probability of compromised structural
integrity, which could lead to:
- structural failure,
- where lumber supports or is used in an environmental
separator, the displacement or failure of required environmental separation
elements, which could lead to the deterioration of building elements,
which could lead to further compromised structural integrity, or
- an inability to resist expected loads, which could lead
- the excessive deformation or deflection of walls, or
- the excessive deflection or vibration of floors.
This is to limit the probability of:
- the space being unsuitable for its intended use,
- compromised operation of windows and doors, and
- damage to the building.