Field study of moisture damage in walls insulated without a vapor barrier. Final report for the Oregon Department of Energy

Technical Report · Thu May 01 00:00:00 EDT 1980

DOI:https://doi.org/10.2172/5376436· OSTI ID:5376436

Tsongas, G. A.

Considerable uncertainty has existed over whether or not wall insulation installed without a vapor barrier causes an increased risk of moisture damage (wood decay) within walls. This report describes the results of one of the first major studies in the country aimed at finding out if such a moisture problem really exists. The exterior walls of a total of 96 homes in Portland, Oregon were opened, of which 70 had retrofitted insulation and 26 were uninsulated and were a control group. The types of insulation included urea-formaldehyde foam (44), mineral wool (16), and cellulose (10). In each opened wall cavity the moisture content of wood was measured and insulation and wood samples were taken for laboratory analysis of moisture content and for the determination of the presence of absence of decay fungi. Foam shrinkage was also measured. To evaluate the possible influence of the relative air tightness of the homes, fan depressurization tests were run using a door blower unit. The field and laboratory test results indicating the lack of a moisture damage problem in existing homes with wood siding in climates similar to that of western Oregon are described along with results of a statistical analysis of the data. Related problems of interest to homeowners and insulation installers are noted. The standard operating procedures used throughout the study are discussed, including the home selection process, quantitative and qualitative techniques used to identify wall locations with the highest moisture content, wall opening and data/sample collection methodology, laboratory analysis of samples, data processing and analysis, and applicability of the results. Recommendations for furutre tests are made. Finally, the potential and desirability for future retrofitting of wall insulation is explored.

• Research Organization: Seton, Johnson, and Odell, Inc., Portland, OR (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5376436
• Report Number(s): ORNL/Sub-78/97726/1
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
THERMAL INSULATION
INSTALLATION
PERFORMANCE TESTING
WALLS
DAMAGE
BUILDINGS
CELLULOSE
MINERAL WOOL
MOISTURE
PLASTIC FOAMS
CARBOHYDRATES
COLLOIDS
DISPERSIONS
FOAMS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
POLYMERS
POLYSACCHARIDES
SACCHARIDES
TESTING
320100* - Energy Conservation
Consumption
& Utilization- Buildings