Presentation on theme: "David Amori, PE, RRC. Description Using negative pressure to simulate and test resistance to wind induced uplift on a membrane roof system."— Presentation transcript:
David Amori, PE, RRC
Description Using negative pressure to simulate and test resistance to wind induced uplift on a membrane roof system.
Test Summary Test pressures are obtained from the structural engineer and/or governing agency. These usually include field, perimeter, and corner test pressures. The apparatus is installed and pressure is gradually increased to the test pressure in 7.5 psf increments (held for one minute) while simultaneously recording the deflection of the membrane. Failure is 0.25 to 0.94 of an inch deflection (FM) and one inch (ASTM).
Test Summary Failure are typically cut open to make observations regarding the failure mode Material Failure Delamination Fastener Pull Substrate Failure
Application Insurability for specific carriers Factory Mutual TWIA Code Compliance New Construction Design Compliance
Application Risk Assessment – as part of the evaluation of a property this test is used to determine probable loss at incremental pressure (Hurricane Strengths).
Relevant Standards ASTM E 907 – 96 (Reapproved 2004): Field Testing Uplift Resistance of Adhered Membrane Roofing Systems FM Global 1-52: Field Uplift Tests