Construction practices for multi-unit wood frame residential buildings in British Columbia, Canada are changing in response to a large number of envelope failures experienced in the period from 1985 to 1999. The new design approach includes the use of enhanced deflection and a drained cavity. While this approach will manage a large portion of the exterior moisture load, we have to assume that some moisture will enter the wall during the life of the building, consequently designs also need to incorporate enhanced drying capabilities. A research program conducted at Forintek Canada Corp.'s western lab in Vancouver, Canada has evaluated the relative drying rates of wall assemblies under controlled laboratory conditions. The research ranks test wall panels in terms of their relative drying capacities, identifies potential wall locations at greater risk of slow drying (thus requiring enhanced material durability) and derives baseline data which can be used to improve parametric models of wall performance.

• wood frame houses and walls, wood structure : drying

1. Designing for durable wood construction: the 4 Ds
2. Envelope Drying Rates Experiment, Final Report  

1. Criteria for unacceptable damage on wood systems
2. Designing for durable wood construction: the 4 Ds
3. Evaluation of vapour diffusion ports on drying of wood-frame walls under controlled conditions
4. Limiting conditions for decay in wood systems
5. Understanding biodeterioration of wood in structures