Buildings XI Conference -- Timber-Frame Walls: Feasible with a Damaged Vapor Barrier? PDF

A ventilated cavity is usually considered good practice for removing moisture behind the cladding of timber-framed walls.
Timber-frame walls with no cavity are a logical alternative, as they are slimmer and less expensive to produce and reduce the
risk of a two-sided fire behind the cladding.

To investigate the possibilities, full-sized wall elements with wooden cladding and different cavity design, type of cladding,
and type of wind barrier were exposed to natural climate on the outside and to a humid indoor climate on the inside. During the
exposure period, parts of the vapor barrier were removed in some of the elements to simulate damaged vapor barriers. The condition
of the wind barriers of elements with intact vapor barriers was inspected from the inside after four years of exposure.

This paper presents results with emphasis on the moisture conditions behind the wind barrier. It was found that the specific
damages made to the vapor barrier as part of the test did not have any provable effect on the moisture content. In general, elements
with an intact vapor barrier did not show a critical moisture content at the wind barrier after four years of exposure.