b'Field-uplift TestingPutting the Test Substantial variability has been found in to the Test field-uplift testingBy Mark S. GrahamThe following article originally appeared in the September 2023 issue of Professional Roof- The specific roof assembly configuration and installation method and test chamber placement ing magazine. It is reprinted with permission from the National Roofing ContractorsAssocia- on the specimens were specifically selected by the ASTM International task force to limit potential tion. variability in materials, installation and chamber placement. In the study, these variables are intended N RCA participated in an ASTM International interlaboratory study to evaluate theto be as constant and consistent as possible so the variability in the test method itselfand not the accuracy and precision of the field-uplift test method. The study provides someroof assemblycan be analyzed.useful data and information for evaluating the appropriateness and effectiveness ofUsing the then-current draft of the ASTM International field-uplift test procedure, each of the field-uplift testing. eight organizations conducted three identical tests in 15-psf increments up to the 90-psf classified uplift rating. The resulting roof assembly deflections during testing were measured and recorded at Field-uplift Testing each increment of each test. Twenty-four specimens of the replicate roof assembly were tested at six There are two recognized field test methods for determining adhered membrane roofpressure increments.systems uplift resistances: ASTM E907, Standard Test Method for Field Testing UpliftThe ResultsResistance of Adhered Membrane Roofing Systems, and FM Global Loss Prevention Data Sheet 1-52 (FM 1-52), Field Verification of Roof Wind Uplift Resistance. In each of theseThe test results show notable variations among testing entities and variations among indi-test methods, a vacuum is created inside a test chamber mounted on a roof surface and mem- vidual specimens results from several of the entities.brane deflections resulting from the induced negative (uplift) pressures inside the chamber are measured.ASTM E907 has been a consensus-based standard since it was originally published in 1983. ASTM International withdrew the standard in 2013 because it lacked a precision statement, which is required for all ASTM International test methods.Unlike ASTM E907, FM 1-52 is a nonconsensus based method for performing field-uplift testing on FM Global-insured buildings where the design wind speeds are equal to or greater than 100 mph (hurricane-prone regions) and in tropical cyclone regions. FM 1-52 also lacks any form of precision statement.ASTM Committee D08 on Roofing and Waterproofing is revising and updating ASTM E907. At the committees June meeting, a draft of the standard, including the results of a newly conducted interlaboratory study assessing the test methods accuracy and precision, was discussed.The StudyAn ASTM International interlaboratory study is a procedure used to obtain a test methods precision statement. It involves multiple laboratories, each generating replicate test results on one or more materials. ASTM E691, Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method, describes the techniques for planning, conducting, ana-lyzing and treating the results of a test methods interlaboratory study. ASTM Internationals staff assists in planning a study and analyzing test results.For the interlaboratory study on the field-uplift test method, eight organizations, including NRCA, volunteered to conduct field-uplift tests using similar test equipment under controlled lab-oratory conditions on a specific roof assembly configuration selected by the ASTM International task force. Replicate roof assembly specimens were constructed and tested at FM Approvals West Glocester, R.I., research facility.The roof assembly configuration selected for the study was a self-adhering, reinforced single-ply membrane over two-inch-thick polyisocyanurate insulation mechanically fastened to a steel roof deck. Each four- by four-foot insulation board was fastened with four fasteners. The tested roof as-sembly has an FM Approvals RoofNav number indicating a Class 90 wind-resistance rating, mean-ing it had been evaluated by FM Approvals to achieve 90-pounds-per-square-foot uplift resistance.18ONTARIO ROOFING NEWSISSUE 4 2023/24 THE ONLY SOURCE FOR PROFESSIONAL ICI ROOFING CONTRACTORS IN ONTARIO ORN'