CLT: Managing Air and Heat

CLT Panels Rarely Remain Airtight

Pressure differences cause air movement across the building enclosure. Movement is caused by a pressure differential between the inner and outer enclosure surfaces, typically attributed to a combination of wind, the stack effect, and mechanical ventilation systems.

Air Barrier Must be Continuous

A continuous air barrier is a requirement of both the 2018 IECC1 and the National Building Code of Canada to control air flow across the enclosure. Limiting the air flow across the CLT enclosure, both inward and outward, has significant performance benefits such as:

• Reduced energy consumption for building heating and cooling
• Improved occupant comfort by limiting drafts
• Reduced risk for interstitial condensation from moisture-laden air
• Minimized transfer of other undesirable substances such as sound, smoke, fire, and pollutants

Durability

An air barrier must be durable to avoid damage that could affect its intended performance during construction and throughout its service life.

System of Materials is Required

The air barrier is not a single component or material but rather requires a system of materials, components, and assemblies that provide continuous air control throughout the building enclosure.