Visit the Energy Systems Laboratory Homepage.
Three Case Studies: Moisture Control in a Hot, Humid Climate
Abstract
This paper will present case studies of the
investigations of three different buildings
exhibiting moisture control problems along the
Gulf Coast. We will briefly discuss the original,
or existing, conditions that led to our
involvement, as well as analysis of the problems,
and recommendations for correction. Each of
these projects would be classified an airconditioned
building in a hot, humid climate, and
subject to the problems and design issues
concomitant with these types of projects.
The first case study was a historic residence in
Houston that had experienced concealed
condensation within the wood-framed floor
system located over a crawl space. The floor
framing had been insulated with an extruded
polystyrene rigid board insulation, but with no
vapor retarder.
The second case study was a new premanufactured
residence located in the pine
woods of Southeast Texas. The residence had
been occupied for two summers when the
occupants began to complain of adverse health
effects. Indoor air quality testing revealed the
presence of mold spores, which prompted the
residents to vacate the premises to allow
appropriate remediation. Our investigation
occurred simultaneously with the remediation
and allowed us to determine the sources of moist
air infiltration that had resulted in the wall
condensation and mold growth.
The final case study was a modern, four-story
office building recently constructed in New
Orleans, Louisiana. The cladding system
consists of a clay brick veneer installed over a
#30 felt weather-barrier, ½” exterior gypsum
sheathing, metal studs with a glass fiber batt
insulation, and interior gypsum board. The
interior finishes consisted of heavy duty vinyl
wall coverings that had been specified by the
architect-of-record. After only two Summer
seasons of occupancy, the building began to
experience fairly widespread mold growth at
specific floor levels. Based upon an extensive
evaluation of the exterior building envelope, it
was found that there were very limited anomalies
pertaining to direct water leakage. Primarily, the
mold growth was associated with inward water
vapor diffusion and moist air infiltration during
the summer months. In addition, it was found
that the interior spaces of a large portion of this
building were experiencing negative pressure
with respect to the exterior conditions.
Remediation of this building for indoor air
quality purposes allowed confirmation of our
initial assessment and appropriate remedial
recommendations have been implemented.
Citation
French, W. R. (2002). Three Case Studies: Moisture Control in a Hot, Humid Climate. Energy Systems Laboratory (http://esl.tamu.edu); Texas A&M University (http://www.tamu.edu). Available electronically from https : / /hdl .handle .net /1969 .1 /4588.