Moisture and subsequent mold problems in
buildings are a serious and increasing concern for the
building industry. Moisture intrusion in buildings is
especially pertinent in hot and humid climates
because the climate conditions provide only limited
drying potential while at the same time providing a
high potential for mold growth. To reduce moisture
accumulation in wall systems, it is important to
design wall systems that not only reduce moisture
intrusion, but also allow drying. Yet often a wall's
ability to dry is not considered during the design or
material selection process. No cladding system or
installation is perfect, therefore wall systems should
be designed with the assumption that some moisture
will enter and then consider the effects and how that
moisture can be managed. This paper explores the
mechanisms of wall drying, focusing on how wood
frame walls dry in hot, humid climates. This paper
describes laboratory drying studies of conventional
sheathing / weather resistive barrier systems under a
variety of temperature and humidity conditions
including those typical of hot humid climates.
Additionally, a computer simulation is used to
examine the implications of drying to the interior,
drying to the exterior, or drying to both the interior
and exterior. Traditional rules of thumb for
construction in hot humid climates rely on drying to
the interior, but we will show that walls can and do
dry to the exterior in these climates