Wind Uplift Behavior of Mechanically Attached Single-Ply Roofing Systems: The Need for Correction Factors in Standardized Tests
Publication: Journal of Structural Engineering
Volume 134, Issue 3
Abstract
In the United States, currently there are three consensus test methods for determining the wind uplift capacity of mechanically-attached single-ply roofing membrane systems. Each is based upon a specific specimen size and static loading regime. However, few studies have examined the relationship, if any, of failure loads among these methods. This study was conducted to determine the effects of varying specimen sizes on the static wind uplift performance or failure loads of mechanically-attached single-ply roofing membranes. Full-scale wind uplift pressure tests were performed in three phases, using six specimen sizes, and three membrane materials. The results were used to determine the minimum acceptable specimen sizes to be used for testing. In Phase 1, fastener failure loads were monitored, while in Phases 2 and 3, the failure experiments were repeated without measuring fastener loads. A significant difference in the apparent failure loads occurs among different specimen sizes for the same membrane materials. The results suggest that correction factors are necessary for comparing tests on different test beds and that the performance of membranes in the test chamber may not produce the same results on full scale structures.
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Acknowledgments
The writers acknowledge the support for Phase 1 testing sponsored by the Federal Emergency Management Agency (FEMA), the State of South Carolina, Carlisle-Syntec Incorporated, and the National Roofing Contractors Association. Test specimens were donated by Carlisle-Syntec Incorporated and Sarnafil Inc. Research sponsorship and materials for the experimental tests conducted in Phases 2 and 3 were provided by Milliken and Company.
References
Baskaran, A., Chen, Y., and Vilaipornsawai, U. (1999). “A new dynamic wind load cycle to evaluate flexible membrane roofs.” J. Test. Eval., 27(4), 249–265.
Baskaran, A., and Molleti, B. (2005). “Application of numerical models to evaluate wind uplift ratings of roofs: Part II.” Wind Struct., 8(3), 213–233.
Baskaran, A., and Nabhan, F. (2000). “Standard test method for the dynamic wind uplift resistance of mechanically attached roofing systems.” Internal Rep. No. IRC-IR-699, National Research Council Canada, Ottawa.
British Board of Agrément (BBA). (1991). UEAtc supplementary guide for the assessment of mechanically-fastened roof waterproofing, British Board of Agrément, Watford, U.K.
Canadian Standards Association (CSA). (2004). “Standard test method for the dynamic wind uplift resistance of mechanically attached membrane-roofing systems.” CAN/CSA-A123.21-04, Mississauga, Ont., Canada, 52.
Factory Mutual (FM). (1992). “Approval standard supplement No. 2 Class Number 4470 Class I roof covers.” Factory Mutual Research Corporation, Norwood, Mass.
Good, C. (2005). “Surveying the roofing market: NRCA’s latest market survey shows 2004 was a solid year for roofing contractors.” Prof. Roof. Mag., 35(4), 24–25.
Kulkarni, A. S. (2005). “Evaluation of mechanically attached single-ply membranes based on tear resistance and weld strength under wind uplift conditions.” MS thesis, Clemson Univ., Clemson, S.C.
Laaly, H. O., and Dutt, O. (1985). “Single-ply roofing membranes.” CBD-235, Canadian Building Digest, Ottawa.
Malpezzi, J. A., and Gillenwater, R. J. (1993). “Static-vs-dynamic: A wind uplift testing study.” Proc., 10th Conf. on Roofing Technology, National Roofing Contractors Association, Gaithersburg, Md.
National Roofing Contractors Association (NRCA). (1997). “National roofing contractors association 1996–1997 annual market survey.” NRCA, Rosemont, Ill.
Prevatt, D. O. (1998). “Wind uplift behavior of mechanically-attached single-ply roof membrane systems.” Ph.D. dissertation, Clemson Univ., Clemson, S.C.
Prevatt, D. O. (2003). “Wind load design and performance testing of exterior walls: Current standards and future considerations.” Performance of exterior building walls, P. G. Johnson, ed., ASTM International, West Conshohocken, Pa., 17–41.
Smith, G. A. (1989). “How sample size affects factory mutual results.” Proc., of Roof Wind Uplift Testing Workshop, Oak Ridge National Laboratory, Oak Ridge, Tenn.
Smith, T. L. (1995). “Insights in metal roof performance in high-wind regions.” Prof. Roof. Mag., 25(2), 12–16.
Smith, T. L. (1996). “High-wind performance of mechanically-attached single-ply roof systems.” Prof. Roof. Mag., 26(2), 18–22.
Smith, T. L. (2005). “The Hurricanes of 2004: An overview of FEMA’s findings and recommendations for roof system performance.” Prof. Roof. Mag. 35(9), 22–27.
Stamm, J. S. (2004). “Evaluation of single-ply mechanically attached roof membrane systems under wind uplift conditions.” MS thesis, Clemson Univ., Clemson, S.C.
Underwriters Laboratory (UL). (1988). “Subject 1897: Outline of investigation for uplift resistance for roofing systems.” Underwriters Laboratory, Inc., Northbrook, Ill.
Warshaw, S. W., and Hoher, K. (1985). “Mechanical fastenings of single-ply roof membranes into steel decks—An engineering evaluation.” 2nd Int. Symp. on Roofing Technology, National Roofing Contractors Association, Gaithersburg, Md.
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Copyright
© 2008 ASCE.
History
Received: Jun 28, 2006
Accepted: Jul 23, 2007
Published online: Mar 1, 2008
Published in print: Mar 2008
Notes
Note. Associate Editor: Kurtis R. Gurley
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