Moisture design to improve durability of low-slope roofing systems

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:426955

Desjarlais, A ^[1]; Byars, N ^[2]

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1. Oak Ridge National Lab., TN (United States)
2. Univ. of North Carolina, Charlotte, NC (United States)

The roofing industry has traditionally held that moisture control in low-slope roofing comprises two independent elements: (1) provide a waterproof exterior covering (or membrane) to protect the low-slope roof from external sources of moisture and (2) perform a condensation calculation to determine if a vapor retarder is required to protect a roof system from internal moisture sources. The first criterion is assumed to be satisfied if a membrane system is specified; in reality, all membrane systems eventually fail, and existing moisture control strategies offer no mechanism for analyzing the inevitable failure. The means of assessing the second criterion, the need for a vapor retarder, has evolved in recent years. The criteria have become more liberal with time because it has been observed that roofing systems installed in a geographic area in which the old criteria required a vapor retarder, have performed well without one.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States)
• DOE Contract Number: AC05-96OR22464
• OSTI ID: 426955
• Report Number(s): CONF-9610200--1; ON: DE97001736
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
CALCULATION METHODS
LEAKS
MEMBRANES
MOISTURE
ROOFS
SEASONAL VARIATIONS
SERVICE LIFE
THERMAL INSULATION
VAPOR CONDENSATION