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, or
• 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, or
• 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.

This is to limit the probability of harm to persons.

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, or
• 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 to
  • 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.

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, or
• 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, or
• 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 compromised structural integrity.

Where lumber supports or is used in floors, this is to limit the probability of excessive deflection or vibration of floors, which could lead to a loss of balance, tripping or falling, which could lead to harm to persons.

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, or
• the exposure of other materials that are moisture-sensitive and susceptible to decay to high moisture levels and decay fungi.

Where lumber supports or is 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 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 loss of lumber strength, or
• the exposure of other materials that are moisture-sensitive and susceptible to decay to high moisture levels and decay fungi.

Where lumber is used in assemblies that are required to provide fire resistance, this is to limit the probability of the compromised fire resistance of the assembly, which could lead to harm to persons.

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, or
• 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, or
• 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 compromised structural integrity.

This is to limit the probability of:

• the excessive deformation of walls, ceilings and roofs, and
• deflection or vibration of floors.

This is to limit the probability of negative effects on the psychological well-being of persons.